Instant Pot Spiced Short Ribs

Name: Instant Pot Spiced Short Ribs
Ingredients: 3 lb. bone-in beef short ribs (about 6 short ribs); 1 tablespoon kosher salt, divided; 1 tablespoon olive oil; 1 onion, chopped (1½ cups); 4 carrots, cut into 1½-in. pieces (about 2 cups); 2 stalks celery, chopped (about ¾ cup), plus leaves for serving; 2 serrano chiles, seeded and finely chopped (1 Tbsp.); 2 tablespoons dark brown sugar; 1 ½ teaspoon ground allspice; 1 cup unsalted beef stock; 1 15-oz. can great northern beans, drained and rinsed