Set your Instant Pot to saute and add oil. Add pepper and onion, as well as garlic. Saute for 2-3 minutes or so.
Add ground beef and stir, cooking until it browns.
Once browned, add Worcestershire, flour, Italian seasoning and salt and pepper.
Cook on high pressure for 5 minutes. Once done, carefully quick release the pressure.
Add in American cheese. Stir to incorporate until the ground beef mixture reaches a creamy consistency.
Remove to an oven-safe dish and place under the oven broiler for just a couple of minutes. Serve, and enjoy!