Pumpkin Seeds (Pepitas): Pumpkin seeds were used in pre-Columbian cooking. They are an important ingredient in moles, pipián (pumpkin seed sauce) and other Mexican dishes. They are often sold roasted and salted. With the white hull removed, pepitas are green and mild flavored.
Cilantro: Introduced by the Spanish, the herb cilantro is the green leaves of the coriander plant. Fresh cilantro is featured in many Mexican dishes and is a must in salsas. Cooked, it begins to lose its anise-like flavor, which is why it's typically added to dishes just before serving. Do not substitute dried cilantro for fresh.
Chayote Squash: Also called a "vegetable pear," chayote are mild-flavored, pale green squash with a thin skin that can be smooth or prickly, depending on the variety. Chayote can be eaten raw, stuffed, pickled, or fried. Smooth-skinned chayote don't require peeling.
Garlic: A member of the lily family (along with leeks, chives, onions and shallots) garlic is the strongest-flavored, most assertive member of the group. Spanish conquistadores brought garlic to Mexico; today, garlic adds bold flavor to rubs, marinades, soups, and sauces.
Citrus: The Spanish introduced citrus into Mexico. The bright flavors of lemons, limes, and bitter Seville orange are integral to many Mexican dishes, from salsas to tortilla soups to ceviches. If Seville oranges are unavailable, you can approximate their distinctive, tart flavor by combining a little grapefruit, lime, and orange juice in equal amounts. Small Mexican limes enliven meats, corn dishes, and add refreshment when squeezed into a bottle of cold Mexican lager.