Chicken & Cheese Tostado

6 flour tortillas (6 inch)
1 pkg. (1-1/4 oz.) TACO BELL® HOME ORIGINALS® Taco Seasoning Mix, divided
1 lb. boneless skinless chicken breasts, cut into 1/2-inch pieces
1/2 cup water
2 large tomatoes, chopped, divided
1 pkg. (7 oz.) KRAFT FREE Shredded Non-Fat Cheddar Cheese, divided
6 Tbsp. BREAKSTONE'S Reduced Fat or KNUDSEN Light Sour Cream
1/4 cup chopped cilantro
make it!
HEAT oven to 400°F.

PLACE tortillas in single layer on large baking sheet; spray with cooking spray. Sprinkle with 1 tsp. seasoning mix. Bake 7 to 8 min. or until tortillas are crisp and golden brown.

MEANWHILE, combine chicken, remaining seasoning mix and water in large skillet. Bring to boil on medium-high heat; simmer on medium-low 5 min. or until chicken is done, stirring occasionally. Add 1-1/2 cups tomatoes; cook until heated through, stirring occasionally. Remove from heat; stir in 1-1/4 cups cheese.

SPOON chicken mixture onto tortillas; top with remaining ingredients.