MIX salsa, pineapple and mango.
PLACE spinach evenly in 13x9-inch baking dish; top with fillets. Spoon 2 Tbsp. of the salsa mixture over each fillet; cover with foil. Set remaining salsa mixture aside for serving with fish.
BAKE at 450°F for 15 minutes or until fish flakes easily with fork. Serve with reserved salsa mixture.