This is a good marinade for steak fajitas
1/2 teaspoon grated Mexican lime peel
1/2 cup Mexican lime juice
1/4 cup gold tequila or beer
4 cloves garlic, minced
1/2 teaspoon pepper
1/2 teaspoon salt
In a nonreactive bowl, stir together all ingredients. Pour marinade over the uncut meat. Refrigerate, covered, for at least 30 minutes or up to 24 hours, stirring occasionally.
When ready to slice and sauté the meat, drain and discard the marinade.