Drizzle 1 tablespoon olive oil in the bottom of slow cooker. Lay chicken on the olive oil and sprinkle with taco seasoning mix.
Add canned tomatoes, black beans, corn, and enchilada sauce to the slow cooker
Heat 1 tablespoon olive oil in a skillet over medium-high heat. Cook onions, garlic, and red pepper until softened. Add to slow cooker.
If desired, top with zucchini and then pour chicken stock over all.
Cover the slow cooker and cook on low for 6 to 8 hours or high for 3 to 4 hours.
Carefully remove the chicken breasts and shred with two forks. Return the chicken to the slow cooker and stir in with cheese dip.
Serve with various toppings.