I ate at McDonald's in 5 different countries and discovered how the fast-food giant has won over customers worldwide

My first international McDonald's was in South Korea, where I visited a location in Seoul's busy Myeongdong neighborhood.

The bustling location had English phrases covering the walls and convenient ordering kiosks.

I ordered the egg bulgogi burger, corn chowder, curly fries, the McChicken Mozzarella, a Coke Zero, and a Green Grape Chiller.

I had high hopes for the mozzarella-topped chicken sandwich, but was massively disappointed. The sweet, tomato-flavored sauce overwhelmed any other flavor, and the mozzarella quickly devolved into a rubber texture.

The curly fries were far better. They were almost as good as Arby's fries, which I consider the gold standard.

The corn chowder was sweet and comforting, offering a great example of how McDonald's can make tweaks to meet local tastes in a non-showy manner.

The Slurpee-esque Green Grape Chiller wasn't anything special but did leave me wondering why the US has only embraced purple grape flavoring for sweets.

The bulgogi burger far outshone McDonald's other South Korean menu items. Made with pork and flavored with a sweet sauce, the burger was created to win over Korean customers.

This version was topped with an egg, which looked as if it could have been plucked straight from a McMuffin. It was a bit chalky and didn't add much to the burger.

So, I decided to return to McDonald's before leaving Seoul to order another bulgogi burger. I'm happy I did — it's a soft and rich burger, spiked with the sweet, goopy sauce.

And, when ordering my second round of McDonald's in South Korea, I couldn't resist a side of fries, which are just as tasty in Seoul as they are in the US.

Read more: I went to McDonald's in South Korea and discovered why it's a worthy destination for any fast-food-obsessed American visiting the country

If you're in South Korea, I would suggest getting the bulgogi burger to understand how McDonald's adapted its menu to win over locals, as well as get a rough understanding of what Korean customers are looking for when it comes to fast food.

Cost of egg bulgogi burger, fries, and a drink: 8,400 Korean won or $6.90

Rating: 6.5/10

Standouts: Bulgogi Burger, Curly Fries

Avoid: Mozzarella McChicken

Next, I visited Ho Chi Minh City, Vietnam. While fast-food chains have struggled in Vietnam, where incredible street food is on every corner, there are a handful of McDonald's locations in the city.

Like in Seoul, the McDonald's I visited in District 1 was polished and clean. There was also a substantial McCafe counter, serving up various colorful drinks.

I ordered off the "rice" menu, which includes options such as rice and fried chicken and the "McSpicy," which appears to be spicy nuggets with rice.

I ordered the grilled pork rice and a matcha frappuccino — size "tall."

The frappuccino wouldn't feel out of place on a Starbucks menu. It's sweet, with a nice mellow flavor from the matcha.

The rice and pork are probably less likely to hit American menus. That's a shame, because it was quite a tasty dish, even if it is just some white rice with a McMuffin sausage sliced up on top of it.

If you're a Sausage McMuffin fan, you'll love the greasy goodness of sausage on top of white rice. As someone who ranks Sausage McMuffins as a top-five McDonald's menu item, I wolfed this down.

The garlic soy sauce basically exactly what it says on the package, but a nice addition you won't find at an American McDonald's.

Like the bulgogi burger, McDonald's Vietnam's rice menu is a great example of how the chain adjusts to local tastes. With so much great street food in Vietnam, you probably don't need to visit McDonald's. But, the chain is putting up a good fight to win over customers anyway.

Cost of rice and pork, plus a frappuccino: 106,000 Vietnamese dong, or $4.59

Rating: 7/10

Standouts: Rice menu

Avoid: Don't visit McDonald's until you've already enjoyed plenty of Vietnamese street food (I recommend the Back of the Bike tour for a good primer)

Next, in my whirlwind McDonald's world tour was Malaysia. I decided to stop by Suria KLCC, the massive mall next to the Petronas Twin Towers, and check out the McDonald's selection.

While I was intrigued by the stand-alone ice cream shop, I continued into the main McDonald's location. It was another sleek, kiosk-heavy shop in a tourist-friendly area.

And, yet again, I was sucked in by the local offerings.

I ordered one nasi lemak and Milo, a chocolate malt drink that's popular in Australia and part of Asia and Africa.

The Milo basically tasted like chocolate milk. So, no complaints here.

McDonald's avoided the nasi lemak debacle that was served up on VietJet when crafting the fast-food version of the iconic Malaysian offering. The sauce had a nice kick, and the dish featured actual dried sardines.

Read more: I flew on Vietnam's award-winning budget airline known for its bikini-clad flight attendants 3 times in one week, and it was an emotional rollercoaster

The fried chicken was pretty much fast-food standard, without much to set itself apart from the competition. And, the egg was clearly McMuffin-ready, though this one avoided the chalky, rubbery trap many McDonald's eggs fall into.

Overall, it was a solid nasi lemak, more interesting for the novelty than actually superior to options you can order elsewhere in Kuala Lumpur.

Still, the promise of "McDip" ice cream cones caught my eye. I had noticed McDonald's locations in Malaysia were covered in ice cream branding, and I was determined to find out more.

I stopped by another McDonald's location in the Bukit Bintang area. McCafe was front and center yet again, and this location had an entire section dedicated to ice cream.

McDonald's was advertising five McDip flavors — mango, caramel, chocolate, taro, and matcha. This location was out of everything but chocolate and matcha, so I decided to order the green-coated ice cream.

The matcha dip quickly hardened into a Magic Shell-like outer coating. It added a nice rich, almost earthy taste to the iconic McDonald's soft serve.

Plus, it just looked fantastic. I wish the other flavors had been in stock so I could have bought up an entire rainbow of McDonald's ice cream cones.

While the nasi lemak showed McDonald's willingness to adapt to local tastes, the McDip was the winner of the day and the highlight of McDonald's Malaysia menu.

Cost of nasi lemak, plus a Milo: 14.70 Malaysian ringgit, or $3.50

Rating: 7.5/10

Standouts: McDip, which should be added to the American menu

Avoid: I didn't find anything I truly hated here

Next up — McDonald's in Thailand.

I visited a McDonald's in Phuket near the busy Patong Beach with my friend Kristie.

We ordered an impressive spread: a Pork Samurai Burger, McWings, Onigiri Shake Fries, a Lychee Sakura Float, a Hello Kitty chocolate sundae, a cheesy spinach pie, and a pineapple pie.

The pork burger reminded me of a cobbled-together version of McDonald's meals past. The pork patty closely resembled a McMuffin sausage, the sauce was similar to the bulgogi burger from the Korean menu, and the bun was just the same as any other McDonald's burger.

It was more interesting than actually good, but interesting nonetheless.

McDonald's sells McWings in Thailand, so we put in an order for three.

The wings were pretty classic fast-food fare — not remarkable, but tasty with good spice levels.

In a slightly confusing twist, the McDonald's we visited in Thailand was marketing a "Japan" menu, which included Onigiri Shake Fries.

While the fries had a hint of seaweed, the strongest flavor was barbecue. Shake fries are always a treat, and this variation was no exception.

I was eager to try the spinach and cheese pie, hoping for a savory treat that matched McDonald's iconic apple pie.

Unfortunately, the filling was more soupy than substantial and strangely sweet.

While the pineapple pie looked cute, I suspected it would be too sweet to actually enjoy.

But, the pineapple flavor was actually perfectly calibrated. It reminded me of Disney's Dole Whip, one of the highest compliments I can offer a dessert.

The Lychee Sakura Float, on the other hand, was disgustingly saccharine.

The Hello Kitty sundae was cute and tasted exactly like a McDonald's sundae you can get in the US. Still, very cute!

Also extremely cute: the Hello Kitty/Fruit Mart Happy Meal toys. If anything, they were too cute. The aggressive levels of love-ability made Kristie cry.

I wouldn't go out of my way to try McDonald's in Thailand. But, if you are craving fast food, the menu offers up some good options.

Cost of a Samurai Burger, Onigiri Fries, and a Coke Zero: 285 baht, or $9

Rating: 6.5/10

Standouts: Wings, pineapple pie, and toys

Avoid: Spinach cheese pie and Lychee Sakura Float

Finally, there was just one country left on my trip — Australia.

As had become my habit, I loaded up on menu items that I could not find in the US.

That meant an order of the Chicken McBites, a nice little take on popcorn chicken. I'm a McNugget purist but quite liked these as a side.

It also meant ordering the McVeggie, a veggie burger that swaps the traditional beef patty for with a potato, cheese, and veggie patty.

The McVeggie patty was essentially a hash brown (great start) mixed with mushy veggies (rough addition). I liked the concept of a veggie burger that didn't try to imitate meat. But, this umami-free puck that would have been better as an actual hash brown.

You can get the McChicken in the US, but in Australia, you can buy it with cheese, listed on the menu as the Chicken 'N Cheese. Kristie signed off on the sandwich as delicious in a classic McChicken-y manner.

The Gravy Loaded Fries united two pretty tasty elements. But, I don't think the gravy was worth the salty, soggy sacrifice of the perfect fry texture that results if you don't eat the fries immediately.

McDonald's Australia menu is basically a slightly higher quality version of what it serves in the US. It doesn't have anything super interesting, but it holds up just fine.

Cost of a McVeggie Burger, McChicken Bites and Fries: 12.65 Australian dollars or $7.98

Rating: 6/10

Standouts: McBites and McChicken

Avoid: McVeggie

After eating McDonald's in five countries, consuming two dozen menu items you can't find in the US, I learned a lot about how the chain has evolved as it takes over the world.

In each country, McDonald's menu mixed American classics with options created to win over local customers.

This results in McDonald's-ified takes on local cuisines, such as a McMuffin egg-topped nasi lemak in Malaysia. Classics like fries and burgers get slight tweaks and upgrades, like shake fries or bulgogi burgers. And sometimes, McDonald's creates something completely new, like the McDip ice cream or the mozzarella stick-topped burger.

As McDonald's expands, the chain needs to stay nimble and continue to adapt to win over customers. And, with McDonald's considering a return of last summer's successful Worldwide Favorites menu in 2020, it's very possible that more of these options will show up in the US soon. \