PREHEAT oven to 425°F. Crumple four large sheets of foil to make four 3-inch balls; place on baking sheet. Place 1 tortilla on top of each ball; spray tortilla with cooking spray. Bake 6 to 8 min. or until tortillas are golden brown. (Tortillas will drape over balls as they bake.)
MEANWHILE, brown meat with chili powder in large nonstick skillet on medium-high heat, stirring occasionally. Stir in salsa and beans; cook 5 min. or until heated through, stirring occasionally.
PLACE 1 tortilla shell on each of four serving plates. Fill evenly with salad greens, meat mixture, cheese and tomatoes. Top with dressing.