Easy Chicken Stew

Name: Easy Chicken Stew
Prep time: 15 min
Cook time: 45 min
Total time: 1 h
Cuisine: American
Ingredients: 1 tablespoon olive oil; 1 tablespoon butter; 1/2 medium onion (chopped); 2 sticks celery (chopped); 3 medium carrots (peeled & sliced); 3 cloves garlic (minced); 2 tablespoons flour; 3 cups chicken broth/stock; 1/2 cup heavy/whipping cream; 2 dashes Italian seasoning; 7 ounces mushrooms (use white or cremini) (sliced); 2 large Russet potatoes (peeled & diced); 1.5 pounds uncooked chicken breasts; Salt & pepper (to taste)