Instant Pot Irish Guinness Beef Stew

Ingredients

• 1 1/2 lbs lean beef stew meat (round chuck), cut into bite-sized pieces
• Salt
• pepper
• 3 tablespoons olive oil, divided
• 8 ounces sliced cremini or baby bella mushrooms
• 1 large yellow onion, diced (about 2 cups)
• 2 celery sticks, diced (about 1 cup)
• 2 cloves garlic, minced (about 2 teaspoons)
• 2 tablespoons tomato paste
• 1 can (14.9 ounces) Guinness or other stout beer
• 2 teaspoons Dijon mustard
• 1 tablespoon Worcestershire sauce
• 1 tablespoon sugar
• 2 bay leaves
• 2 sprigs fresh thyme
• 1 cup beef stock
• 1 1/2 lbs yukon gold potatoes (about 4), peeled and cut into bite-sized pieces
• 4 to 5 carrots, peeled or scrubbed, and cut into 1/2-inch rounds
• 3 tablespoons cornstarch