Instant Pot Short Ribs

Name: Instant Pot Short Ribs
Ingredients: 2 slices bacon, cut into 1 pieces; 5 lb. bone-in short ribs (about 13 to 14 ribs); Kosher salt; Freshly ground black pepper; 4 large shallots, quartered; 4 large carrots, peeled and cut into 3 pieces; 2 stalks celery, chopped; 1/2 tsp. crushed red pepper flakes; 6 cloves garlic, chopped; 2 star anise; 4 sprigs fresh thyme, plus more for garnish; 3 tbsp. tomato paste; 1 c. dry sherry; 2 tbsp. packed brown sugar; 2 tbsp. Worcestershire sauce; 2 tbsp. balsamic vinegar; 2 c. low-sodium beef broth; Mashed potatoes, for serving