Root Beer Short Ribs

Ingredients

• 4 1/2 pounds short ribs, cut into 4-inch pieces
• coarse salt and ground pepper
• 3 tablespoons vegetable oil, plus more as needed
• 2 medium yellow onions, cut into 1-inch wedges
• 3 large celery stalks, cut into 1 1/2-inch pieces
• 2 small carrots, cut into 1 1/2-inch pieces
• 1 head garlic, sliced in half crosswise
• 10 sprigs thyme
• 2 bay leaves
• 1 sprig rosemary
• 1/2 teaspoon ground cumin
• 2 whole star anise
• 3 1/2 cups low-sodium beef broth
• 2 cups good-quality root beer