Until the arrival of the Spanish Conquistadors, much of Mexico's cuisine was identical with that of the rest of Central America, and relied on corn and beans as well as a few meaty additions to provide nutrition.
The arrival of the Spanish saw the addition of many new ingredients to the local menu, including rice and beef - a combination that saw the development of the famous Chilli dishes that dominate Tex-Mex cuisine to this day, and chicken, which is used in many Fajita and Burrito recipes.
Spicy chilli peppers had been used for a long time in Mexican cuisine - it is thought that their use began because they promote sweating and help to cool you down - and this usage developed further over the years, giving rise to the spicy food that we enjoy to this day.
A popular dish in Mexico is refried beans, which comprises of cooked beans being fried in lard with onions and pepper before being mashed and it is served as an accompaniment to many other dishes.