The spices most commonly used in Mexican casserole recipes are chile powder, cumin, oregano, garlic powder and onion powder. Chile powder, the mainstay of Mexican cooking, is a combination of dried, ground chiles, cumin and oregano. These three robust spices balance and complement one another.
Cumin has a distinctive earthy and slightly bitter flavor. Oregano adds a bold, pungent flavor to dishes. Dried, powdered chiles have a wide range of flavor and heat, depending of the type of pepper used and where it was grown. Chipotle, another common Mexican spice, is made from dried, smoked jalapeños, and imparts a rich, smoky flavor to recipes. Mexican recipes sometimes also call for cinnamon, cloves, anise or cocoa to add complexity to the dish.
The hallmark flavors of Mexican casseroles are not limited to spices. Mexican recipes also rely heavily on fresh chile peppers, garlic, onions and tomatoes. Jalapeño, ancho, poblano and habañero are some of the most commonly available chile peppers. Fresh cilantro is frequently used in salsas and garnishes, while the seed of the cilantro plant, coriander, is ground and used as a spice. Another Mexican spice is annato, which is known for its aromatic, slightly peppery flavor and bright orange color.