You can make fajita seasoning in under five minutes at home by combining 1 tablespoon of cornstarch, 2 teaspoons of chili powder, 1 teaspoon of salt, 1 teaspoon of paprika and 1 teaspoon of white sugar in a bowl. With these ingredients, mix 1/2 teaspoon of onion powder, 1/2 teaspoon of garlic powder, 1/4 teaspoon of cayenne pepper and 1/2 teaspoon of ground cumin. Apply this seasoning to fajita meats and vegetables prior to cooking.
For a more complex fajita marinade, prepare the following recipe a day beforehand to allow your meats of choice to marinate in it overnight. The recipe itself requires about 15 minutes to make.
Start by juicing 3 limes, mincing 3 cloves of garlic and, chopping 2 green onions and 3 tablespoons of cilantro. Combine these ingredients in bowl with 2 tablespoons of vegetable oil, 1/2 of a teaspoon of red pepper flakes, 1/4 of a teaspoon of ground coriander and 1/4 of a teaspoon of ground anise seed, if you desire.
Whisk these ingredients until they are well-blended, and pour the resulting marinade over either chicken or beef. Cover the meat, and marinate it for between 12 and 24 hours before cooking. This recipe yields enough marinade for roughly four servings of fajitas.