To serve as a second meal for 4, use a slotted spoon to reserve 2 cups bean mixture, leaving liquid behind. When ready to serve, mash mixture in a bowl with a fork. Coat a lined baking sheet with cooking spray. Arrange 4 pitas in a single layer on pan. Spread bean mixture on pitas. Divide 1½ cups shredded Cheddar cheese among pitas. Bake in 450°F oven 8–10 min., until edges are browned. Serve with salsa and sour cream.