1 tablespoon chili powder
1 teaspoon ground cumin
1/2 teaspoon brown sugar
1/2 teaspoon pepper
1/8 teaspoon salt
1/8 teaspoon garlic powder
1/8 teaspoon chipotle seasoning
1/2 cup Italian dressing
2 pounds top sirloin or flank steak
10 (8-inch) flour tortillas, warmed
Toppings: sour cream, shredded lettuce, chopped tomato, shredded Cheddar cheese
Combine first 8 ingredients in a 1 gallon zip-lock bag, add beef. Refrigerate at least two hours. (I do this in the morning before work.) Remove beef from marinade, discarding marinade.
Grill, covered with grill lid, over medium heat (300° to 350°) about 10 minutes on each side or until desired degree of doneness. Let rest at least 5 minutes. Cut into strips. Serve in flour tortillas with toppings.