Step 1
In large skillet set over medium heat, add oil. Add onion and garlic; cook, stirring occasionally, for 2 to 3 minutes or until softened. Add red peppers, black beans, mushrooms and taco seasoning; cook, stirring occasionally, for 3 to 5 minutes or until vegetables are tender and fragrant.

Step 2
Divide mixture evenly among tortillas. Top evenly with avocado, sour cream, 1 cup TOSTITOS^® Chunky Salsa Mild and, if using, cilantro.

Step 3
Serve fajitas with remaining TOSTITOS^® Chunky Salsa Mild and lime on the side.