Trim fat from meat. Partially freeze meat for about 30 minutes. Thinly slice across the grain into bite-size strips. Place strips in a plastic bag set in a deep bowl.

Meanwhile, for marinade, in a small mixing bowl, combine the 1/3 cup cooking oil, lime juice, jalapeno peppers, green onions, cilantro, salt, and garlic. Pour marinade over beef strips in bag. Close bag tightly; turn to coat beef strips. Marinate in the refrigerator for 2 to 4 hours, turning bag occasionally.

Wrap tortillas tightly in foil. Heat in a 350 degrees F oven about 10 minutes or until heated through.

Meanwhile, drain beef strips; discard marinade. In a large skillet heat the 1 tablespoon cooking oil over medium-high heat. Add onion and sweet pepper. Cook and stir about 3 minutes or until vegetables are crisp-tender. Remove vegetables from skillet.

Add beef to the hot skillet. Cook and stir for 2 to 3 minutes or until done. Drain well. Return all vegetables to skillet. Stir in tomato. Cook and stir for 1 to 2 minutes or until heated through.

To serve, fill warm tortillas with beef-vegetable mixture. If desired, top with guacamole, salsa, and sour cream. Roll up tortillas. Makes 4 servings.

Prepare the filling as directed. Cover and chill for up to 24 hours.