Heat one-tablespoon olive oil in a large non-stick skillet over medium until hot. Add one pound (about six cups) sliced Portobello mushrooms and one each medium green bell pepper and onion cut into strips.

Cook 5 minutes or until vegetables are softened and liquid evaporates.

Meanwhile, combine one package (1/25 ounce) fajita seasoning mix and two tablespoons water. Spoon mixture over six (8-inch), 98-percent fat free flour tortillas, dividing evenly.

Spoon mixture over six (8-inch), 98-percent fat free flour tortillas, dividing evenly. Top with salsa and reduced fat sour cream, if desired.