There are scores of Thai cooking schools in Bangkok, Phuket, Chiang Mai and other parts of the country that can teach even real beginners. Some people enroll for a day because it's fun and they want to eat their creations, others take classes because they're already good cooks and want to learn a little about Thai cuisine. Either way, it's a great activity to do while you're here.
Few people are disappointed after taking a class at any school, but some schools are better than others. Read all about Thai Cooking Schools here.