Tuscan Chicken Skillet

1 lb. chicken breast tenderloins;

1 onion, diced;

3 cloves garlic, minced;

12 oz. mushrooms, sliced;

½ cup sun-dried tomatoes, chopped;

15 oz. fire-roasted diced tomatoes;

1 tsp. oregano;

½ tsp. thyme;

Cooking fat;

Sea salt and freshly ground black pepper;