Place chiles on foil-covered baking sheet. Broil, 4 inches from heat, 7 to 10 min. or until evenly blackened, turning occasionally. Transfer chiles to bowl; cover tightly. Let stand 20 min. or until cooled. Peel chiles; discard skins. Cut lengthwise slit in each chile, being careful to not cut through to opposite side. Remove and discard seeds.