Slow cooker chicken enchilada soup

Chicken second courses

2 boneless skinless chicken breasts (about 1 pound) 2 cups good-quality chicken stock 1 1/4 cup (or 1 10-ounce can) red enchilada sauce* 2 (14-ounce) cans black beans 1 (14-ounce) can fire-roasted diced tomatoes 1 (15-ounce) can whole-kernel corn** 1 (4-ounce) can diced green chiles 2 cloves garlic 1 white onion peeled and diced 1 teaspoon ground cumin 1 teaspoon salt or more/less optional garnishes: chopped fresh cilantro