Heat the olive oil in a large skillet set over medium heat.
1 tablespoon olive oil
Sprinkle salt over the chicken breasts.
½ teaspoon kosher salt, 2 pounds boneless, skinless chicken breasts
Working in batches, brown the chicken breasts for 2 minutes on each side, but don’t cook through.
Set chicken aside on a plate.
Add the crushed tomatoes, tomato paste, wine, Italian seasoning, onion, bell peppers, and garlic to the slow cooker. Stir to combine.
28 ounces crushed tomatoes, 4 ounces tomato paste, ½ cup white wine, 1½ teaspoons Italian seasoning, ½ onion, 2 bell peppers, 3 cloves garlic
Add in the seared chicken.
Cook on high for 3-6 hours, or on low for 6-8 hours.
Add in the mushrooms and cook on low for 30 minutes until the mushrooms are tender.
8 ounces cremini mushrooms