Preparation Preheat broiler. Arrange chilies on baking sheet. Broil until charred on all sides, turning occasionally, about 20 minutes. Enclose in paper bag; let stand 10 minutes. Peel chilies. Cut 1 lengthwise slit in each chili; carefully remove seeds. Meanwhile, heat oil in large nonstick skillet over medium-low heat. Add onions; sauté until golden, about 20 minutes. Season with salt and pepper. Spread onions evenly in 13x9x2-inch glass baking dish. Preheat oven to 350°F. Mash half of beans with cayenne in medium bowl. Mix in remaining beans. Spoon mixture into chilies. Arrange chilies seam side down atop onions. Sprinkle cheese over. Cover with foil. (Can be made 4 hours ahead. Chill.) Bake chilies 15 minutes. Uncover; bake until cheese melts, about 5 minutes longer. Serve each with salsa and 1 tablespoon sour cream. Per Serving: calories, 219; total fat, 5g; saturated fat, 2g; cholesterol, 8mg. Nutritional analysis provided by Bon Appétit
Preparation Preheat broiler. Arrange chilies on baking sheet. Broil until charred on all sides, turning occasionally, about 20 minutes. Enclose in paper bag; let stand 10 minutes. Peel chilies. Cut 1 lengthwise slit in each chili; carefully remove seeds. Meanwhile, heat oil in large nonstick skillet over medium-low heat. Add onions; sauté until golden, about 20 minutes. Season with salt and pepper. Spread onions evenly in 13x9x2-inch glass baking dish. Preheat oven to 350°F. Mash half of beans with cayenne in medium bowl. Mix in remaining beans. Spoon mixture into chilies. Arrange chilies seam side down atop onions. Sprinkle cheese over. Cover with foil. (Can be made 4 hours ahead. Chill.) Bake chilies 15 minutes. Uncover; bake until cheese melts, about 5 minutes longer. Serve each with salsa and 1 tablespoon sour cream. Per Serving: calories, 219; total fat, 5g; saturated fat, 2g; cholesterol, 8mg. Nutritional analysis provided by Bon Appétit