Set a saute pan or indoor grill pan over medium-high heat. Warm pitas on each side until golden and heated through, about 2 minutes.
Lay all four pitas flat. Spread 1/4 cup hummus in the middle of each pita. Top with roasted red peppers, avocado, cucumber, onion, and lettuce. Top with a dash of salt and pepper, if desired. Fold in half and serve.