Thanks to my time serving tables at Bangkok City in Boston, I can guarantee you Americans know more about Thai food than pad thai and tom yum kung, though I can’t deny that in six short months I probably received thousands of orders demanding these two items.

It always made me happy—even more so than a generous tip—when my customers ordered something a bit more adventurous. If you are one of the people who orders things like yen ta fo (pink noodle soup) for lunch or larb moo, som tum, and sticky rice for dinner, please know that you have the power to electrify my mood when I serve your food. Also, congratulations! You have passed Thai Food 101. Are you ready for the next class?

The next lesson is a little more advanced: We’re going to talk about foods that are pronounced and spelled the same, but, depending on where you order them, command entirely different meals. The majority of the Thai dishes served outside Thailand are from the Central region. During the past decade, however, many new restaurants have decided that their main stars would be recipes from the Northeastern region instead.

If you are a regular at any Northeastern-style place, where they serve what the Thais call Isan food, my guess is you are familiar with words like larb and som tum. If you’ve ordered these dishes so often that you don’t need a menu, then you are probably confident that wherever you are in Thailand, these two words are going to get you your favorite spicy salads.

The good news is that you are right. The bad news is that you are not necessarily right if you are in Northern Thailand, where you will recognize familiar names but not what ends up on your plate.

Larb vs. Larb

Larb is a word for an Isan spicy salad. On the menu it is followed by a word that indicates the kind of meat you’ll have. For example, larb moo is spicy pork, larb ped is spicy duck, larb gai is spicy chicken, and larb nua is spicy beef. All recipes require minced meat and have a tangy flavor from the roughly ground red chilies, lime juice, and fish sauce. Toasted, ground rice adds another layer to the aroma. This is the kind of larb most Thais think of, and it is the same kind that appears on menus outside Thailand.

Northern larb includes minced pork as well as offal and uncooked pork blood. It’s available in a raw version as well. The beef version likewise requires offal and raw blood, plus bile, which adds a pleasurably bitter taste to the dish. Thanks to a blend of dried spices, these ingredients work well as a team. The spices extract the subtle, sweet flavor of the blood and add a hard-to-resist aroma. Although it smells so good that you want to try a big bite at once, beware the mouth-numbing effect of prik larb, or Northern chili paste.

Gaeng Om vs. Gaeng Om

Gaeng in Thai means “curry.” That’s why we have so many gaeng items in our culinary lexicon. Among hundreds of these spicy soups, however, the North and Northeast peoples happened to give their famous curries the same name, which is gaeng om.

Northeastern gaeng om can be considered a healthy dish on account of the wealth of vegetables—cabbage, long bean, betel leaf, among others—in each serving. The spicy soup also has meat, but vegetables are the main character. But the pla ra, or fermented fish, steals the show. The condiment has an extremely strong flavor and a love-it-or-hate-it smell.

Northern gaeng om is almost like the opposite of its Northeastern counterpart since meat such as beef, pork, and buffalo plays an important role. Aromatic notes are provided by plant matter such as galanga, lemongrass, kaffir-lime leaves, and spring onion. But they are there more to add herbal fragrance than to govern the flavor. Also, no pla ra here. Kapi, or salted shrimp paste, snatches that role and is less potent than pla ra, so this gaeng om may be easier to eat if you’ve never tried it.

Som Tum vs. Som Tum

I grew up and have spent most of my life having som tum thai in the Central Thai style and som tum pla ra in the Isan style without knowing that Northern people have their own take on spicy papaya salad. The Northern-style ingredient that puts this item on my list is nam pu, a regional household condiment. You just won’t find it in other som tum.

While som tum thai keeps the flavor fresh, spicy, sour, and a little sweet, som tum pla ra is immensely intense with fermented fish. The nam pu in Northern-style som tum lends the distinct flavor of freshwater paddy crabs, usually caught in the rainy season. The crabs are mixed with lemongrass, turmeric leaves, and rock salt, then braised for hours to form a fermented paste. Since the color of nam pu is black, it makes Northern-style papaya salad darker than its cousins.

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Jiaw vs. Jiaw

If you talk to any Thais and ask about the word jiaw, chances are they will think that you want to discuss the popular kai jiaw, or Thai omelet. The only exception will be the person from Northern Thailand whose family cooks in the Lanna tradition.

Jiaw is a common word for frying in a pan using cooking oil. Not many people even in Thailand know that the word is used in the North to describe a totally different act in the kitchen. For people in the North, jiaw is about boiling ingredients such as moringa leaves and spinach, and no oil is required. In that boiling pot, vegetables are seasoned with salted shrimp paste, garlic, shallot, and chili. Egg can also be part of the action, but it’s optional.

Gaeng Gluay Dib vs. Gaeng Gluay Dib

Let’s go beyond Northern, Northeastern, and Central Thailand to explore the remaining region: the South. Although it’s Northeastern and Northern dishes that usually have twinned terms, people in the South share a word with people in the North. That’s why gaeng gluay dib, or unripe banana curry, is on this list.

Cultivated banana is paired differently in different locations. For Southern palates, the banana is cooked with coconut milk. The meat can be beef, pork, or chicken. All goes well with the strongly spicy flavor of fresh bird’s eye chili. In the Northern version, the very same unripe banana is best matched with pork belly and cha-om, or climbing wattle. The piquant flavor is a nice mix of salted shrimp paste, fermented fish, and dried chili.

My mom is native to the South and once described this dish to me; she had no idea that her favorite gaeng gluay dib was available in a different form until I told her.

Even though I was born, grew up, and have lived most of my life in Thailand, “So you think you know Thai food?” is actually a question that I keep asking myself. The wordplay of these dishes proves that there is a lot more to learn and a lot to explore, especially on the subject of Northern Thai food.