Wash the 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, tomato sauce and salt and pepper.
Mix well to obtain a homogeneous mixture and stuff the peppers with this it.
Clean the bottom of the Instant Pot and then add water.
Place the trivet inside the Instant Pot and then place your stuffed peppers onto the trivet.
Cook at high pressure for about 5 minutes, depending on the size of your peppers.
After cooking ends, let the pressure release naturally.
Carefully take the peppers out and place them on a baking tin.
Spread with shredded mozzarella and put in the oven.
Bake in grilling mode (180°c or 350°f) for a couple of minutes, until cheese melts.