Nam pla is a sauce based on preserved seafood, normally anchovies, but at times they also use dried shrimp. It is found in most Thai or Vietnamese kitchens and is a vital ingredient for hot and sour soup.

Toasted sesame oil is common in Vietnamese cooking for a fresh sauce, added to fresh lime juice, a dash of soy sauce, some chopped fresh green chili and scallions along with a pinch of sugar.  It goes especially well with spring rolls and lettuce wraps.

Rice is an essential accompaniment to most southeast-Asian meals. Try adding sweet rice vinegar as a condiment to the rice.

Coconut milk, lemon grass, chili and kaffir lime leaves are widely used. Thai basil is also popular, and has a very different flavor than Mediterranean basil.

Keep in mind that Southeast Asia covers Cambodia, Indonesia, Laos, Malaysia, the Philippines and Vietnam, so food does vary from one region to another. Thai food is the most popular cuisine coming out of this region.