- 4 skinless, boneless chicken breast halves
- 1 (28 ounce) jar spaghetti sauce (such as Classico® Cabernet Marinara with Herbs)
- 1 (6 ounce) can tomato paste
- 1/4 pound sliced fresh mushrooms
- 1/2 yellow onion, minced
- 1/2 green bell pepper, seeded and diced
- 3 tablespoons minced garlic
- 1 1/2 teaspoons dried oregano
- 1/2 teaspoon dried basil
- 1/2 teaspoon ground black pepper
- 1/4 teaspoon red pepper flakes (optional)
- Place chicken in a slow cooker; stir in spaghetti sauce, tomato paste, mushrooms, onion, bell pepper, garlic, oregano, basil, black pepper, and red pepper flakes. Cover.
- Cook on Low until chicken is tender, 6 to 8 hours.