Wash your peppers, cut off their tops and deseed them carefully.
Pour olive oil into your Instant Pot and press “Sauté”:
Add ground beef and cook for 2 minutes, until meat browns slightly.
Place your browned beef into a large bowl and add cooked rice, minced onion, whisked egg, Worcestershire sauce, garlic, thyme, Italian seasoning, paprika, salt and pepper.
Mix well to obtain a homogeneous mixture.
Stuff your peppers with the prepared mixture.
Pour water into your Instant Pot (clean the bottom previously!).
Correctly place the trivet and place your stuffed peppers onto the trivet.
Cook at high pressure for about 10 minutes, depending on the size of your peppers.
Release the steam naturally.
Carefully take your peppers out and place them on a baking tin.
Spread tomato sauce and sprinkle with shredded mozzarella.
Bake in grilling mode for a couple of minutes, until cheese melts.
Serve hot or warm.