Instant Pot Short Ribs

Name: Instant Pot Short Ribs
Ingredients: 1 medium yellow onion; 2 cloves garlic; 2 medium carrots (about 5 ounces total); 1 tablespoon vegetable oil; 4 to 4 1/2 pounds bone-in English-style or thick-cut beef short ribs (each piece no longer than about 4 inches); 1 tablespoon plus 1/2 teaspoon kosher salt, divided, plus more as needed; 1/2 teaspoon freshly ground black pepper; 2 tablespoons double concentrated tomato paste (from a tube); 4 sprigs fresh thyme, or 1 teaspoon dried thyme; 1 bay leaf; 1/2 cup dry red wine; 1/2 cup beef broth; 2 tablespoons cornstarch; 2 tablespoons water; Fresh parsley leaves, for garnish (optional); Serving options: Mashed potatoes , polenta , or buttered cooked egg noodles