Brown Ground Beef & Mushrooms: Press "Saute" button to "Sauté More" to heat up Instant Pot. Wait until it says "HOT" (~8mins) to ensure the pot is as hot as it can be. Add 1 tbsp olive oil (15ml) in Instant Pot, and ensure the whole bottom is coated. Season one side of ground beef with salt and black pepper. Place the whole chunk of ground beef in Instant Pot (seasoned side face down), then add sliced mushrooms to the side. Let the whole chunk of ground beef brown (don't touch it for 5 minutes). Generously season the other side with salt and black pepper. After 5 minutes, chop the ground beef into 6 chunks, then flip to the other side. *Pro Tip: There will be a lot of juice coming out of the beef and mushrooms, let the juices reduce until no juice left (~10 mins). Break the ground beef into small chunks, mix them with the mushrooms, then saute for another 3 minutes.
Saute Onion & Pepper: Add minced onions and 1 tbsp (15ml) regular soy sauce in Instant Pot, then saute for 2 minutes. Add in diced bell pepper (from pepper tops) and 1 tsp (1.2g) dried Italian seasoning, then saute for 2 minutes.
Saute Garlic & Rice: Add in ½ cup - 1 cup cooked white rice, 1 tbsp (15ml) tomato paste, and minced garlic, then saute for 30 seconds. Break up rice clumps and ensure the rice is not sticking together. Remove the inner pot from heat.
Stuff Bell Peppers: While the ingredients are hot, mix in shredded cheddar cheese and mozzarella cheese. Mix 1 can (430g) diced tomatoes into the stuffings. Give it a taste and season if necessary (for reference, we added ¼ tsp fine salt). Fill bell peppers with stuffings.
Pressure Cook Stuffed Peppers: Clean and dry the inner pot. Add 1 cup (250ml) cold water and trivet in Instant Pot. Place the stuffed peppers on the trivet. Close lid, then turn Venting Knob to Sealing position. Pressure Cook at High Pressure for 5 minutes + Quick Release. Open the lid carefully. Optional - Melt Cheese on Stuffed Peppers: Sprinkle cheese on top of the bell peppers. *Air Fryer Method: Place the Air Fryer Lid on Instant Pot Duo Crisp. Press "Air Fry" button, set the temperature to 400°F and cooking time to 8 minutes.*Oven Method: Layer the stuffed bell peppers on a baking sheet, then put them under the broil function for a few minutes.
Serve Stuffed Peppers: Garnish stuffed peppers with finely chopped parsley, then serve immediately. Enjoy :)