Nam Prik Pao (thai chili paste) is a common ingredient used in Thai cooking, especially Tom Yam Koong which is the very famous Thai cuisine.  It is spicy and sweet, with rich flavors of roasted vegetables and is often enriched with shrimp.  
 
It is so common that you might be able to easily find in a jar outside of Thailand. This versatile flavourful paste is used often in Thai cuisine in our soups, stir-fries, salads, and even as a spread!