Instant Pot Salisbury Steak

Bahan-bahan (6 porsi)

• 8 ounces mushrooms (sliced)
• ½ onion (sliced)
• 1 ½ cups beef broth (low sodium)
• 1 ounces brown gravy mix (1 packet, dry)
• 1 tablespoon tomato paste
• 1 tablespoon Dijon mustard
• 2 tablespoons chopped fresh parsley
• 1 tablespoon Worcestershire sauce
• 2 tablespoons cornstarch
• 4 tablespoons water
• 1 ½ pounds lean ground beef
• 1 egg yolk
• ⅓ cup Panko bread crumbs
• 3 tablespoons milk
• salt and pepper to taste