In large bowl, combine all meatball ingredients (meat, eggs, parmesan cheese, bread crumbs, Worcestershire sauce, onion, garlic, paprika, parsley, salt & and pepper). Mix it all together well. Add some oil to your hands to prevent sticking and roll meatballs into about 1 1/2” balls. Try to keep the meatballs all the same size for even cooking.
Turn Instant Pot on "Sauté”. When hot, add oil then add about 6-8 meatballs. Sear in small batches in the Instant Pot. Sear only enough meatballs in a batch so they don’t overcrowd and you have room to maneuver a spatula in-between to flip them while searing.Sear the outside of the meatballs until a crust forms, gently rolling the meatballs around the Instant pot occasionally so that all the sides are seared evenly. Remove the seared meatballs and sear the next batch(s) until all the meatballs are seared.
Add all the seared meatballs into the instant pot. Add the tomato sauce to the pot of meatballs. Close the lid and pressure cook on high pressure for 15 minutes. If you rolled the meatballs larger, cooking time will be longer. (These are the steps we did for our Instant Pot: Close the lid and close the Pressure Release Valve. Press "Cancel" to stop the "Sauté" setting. Press the "Manual" button. Set the time to 15 minutes.)
After the cooking time is complete, press "Cancel" and carefully release the pressure.
Sprinkle with parmesan cheese and parsley. Serve warm with desired accompaniments (pasta, rice, bread, etc...).