Instant Pot Philly Cheesesteak Pasta

Ingredients

• 2 tablespoons salted butter, divided
• 1 tablespoon olive oil
• 2 cups frozen bell pepper and onion mix, thawed
• 9 ounces boneless beef sirloin steak, thinly sliced
• 1/2 cup beef broth
• 3 cups bow-tie pasta
• 1 tablespoon all-purpose flour
• 1/2 cup milk
• 1 1/2 cups shredded American cheese
• salt and freshly ground black pepper to taste
• 1/2 cup sliced fresh mushrooms
• 1 teaspoon Worcestershire sauce
• 1 teaspoon granulated garlic
• 1 teaspoon seasoned salt
• 1/4 teaspoon black pepper