Hearty Beef Stew with Shells

Name: Hearty Beef Stew with Shells
Ingredients: 1 lb. beef stew meat, cut into 1 cubes; kosher salt; Black pepper; 1/4 c. extra-virgin olive oil, divided; 2 carrots, peeled and diced; 2 ribs celery, diced; 1/2 yellow onion, diced; 3 cloves garlic, minced; 2 c. red wine; 4 c. beef stock; 1 14.5-oz. can whole crushed tomatoes; 2 dried bay leaves; 2 sprigs fresh rosemary; 6 sprigs fresh thyme; 2 c. pasta shells; 2 tbsp. unsalted butter; 8 oz. baby bella mushrooms, quartered; 1/2 c. Chopped flat-leaf parsley