Creamy French Chicken Stew

Ingredients

• tablespoon olive oil
• tablespoon unsalted butter
• pounds boneless, skinless chicken breasts
• medium carrots
• small stalks celery
• small onion
• teaspoons fresh thyme leaves
• Kosher salt and freshly ground black pepper
• ounces white or cremini mushrooms
• all-purpose flour
• canned chicken broth or homemade chicken stock
• heavy cream
• Fresh thyme or fresh parsley