PICKLED Onions: Combine all ingredients; cover. Refrigerate overnight.

CHIPOTLE Salsa: Combine all ingredients; set aside.

POLENTA Sopes: Saute onions and garlic in hot oil 5 min. or until tender. Stir in water and salt. Bring to boil. Gradually add polenta, stirring constantly. Reduce heat to medium-low; cook 5 min. or until thickened, stirring constantly. Add cilantro; mix well. Spread to 1/2-inch thickness on bottom of sheet pan sprayed with cooking spray. Refrigerate until firm. Cut into 3-1/2-inch rounds with biscuit cutter.

FOR each serving: Place one polenta circle on greased grill; cook 2 min. on each side or until heated through. Place on serving plate. Top with scant 1/2 cup (3 oz.) Chili-Rubbed Pulled BBQ Pork, 1 Tbsp. each Pickled Onions and Chipotle Salsa, and 1 tsp. cheese. Drizzle plate with 1 Tbsp. barbecue sauce.