In 12-inch skillet, cook beef, onion, poblano chiles and garlic over medium-high heat 5 to 7 minutes, stirring occasionally, until beef is thoroughly cooked; drain.
Spray 5-quart round slow cooker with cooking spray. Reserve ½ cup of the enchilada sauce. Spoon ½ cup enchilada sauce in slow cooker. Stir remaining enchilada sauce, taco seasoning mix, corn and black beans into beef mixture.
Place 1 tortilla in center of slow cooker. Cut 1 tortilla in half; place each half on either side of whole tortilla. Spoon 1 ⅓ cups beef mixture over tortillas; sprinkle with ½ cup cheese. Top with 2 more tortillas, cutting to fit. Repeat layers 3 times with beef mixture, tortillas and 1 ½ cups cheese. Top with reserved ½ cup enchilada sauce and 1 cup cheese.
Cover; cook on Low heat setting 2 hours. Let stand 15 minutes. Garnish with cilantro.
