Instructions

Make your meatballs, then head to the recipe below for the sauce. 

1. Prepare a baking sheet (if freezing). Line a baking sheet that will fit in your freezer with parchment paper and set aside.
2. Make the meatball mixture. Combine ground beef, sausage and eggs in a large bowl. With clean hands, mix together until incorporated. Do not over mix or you will have tough meatballs. Add the breadcrumbs, onion, Parmesan cheese, salt, and pepper; mix again.  
3. Measure and roll your meatballs. For medium-sized meatballs, measure 1 ½ ounces of meat mixture (about 2 ½ tablespoons) and roll into a ball. For smaller cocktail-sized meatballs, measure 1 ounce of meat per meatball. Repeat with the remaining mixture, placing uncooked meatballs on a plate or prepared baking sheet.
4. To freeze the meatballs: Place the baking sheet into the freezer and freeze until firm, about 2-3 hours. Transfer frozen meatballs to a freezer bag. As you seal the bag, press out any remaining air. Store in the freezer for up to 3 months.
5. To cook the meatballs (frozen or unfrozen): Place a trivet into the inner pot of the Instant Pot and add 1 cup of water or beef broth (or 1 ½ cups for 8-quart pot). Carefully place the meatballs you’d like to cook onto the trivet, stacking meatballs between one another into 2-3 layers if needed. Secure the lid, making sure the valve is set to SEALING. Set Instant Pot to Pressure Cook — HIGH for 8 minutes, or 7 minutes for smaller cocktail-sized meatballs. Let the pressure release naturally for 5 minutes; carefully release remaining pressure manually. When done, transfer cooked meatballs to a clean plate. 
6. Make your sauce. While the meatballs cook, make or warm your sauce on the stove. If you’d like to make your sauce in the Instant Pot, you can do it either before or after cooking the meatballs using the SAUTE function. If the latter, remove the meatballs and trivet from the Instant Pot and drain the cooking liquid prior to making the sauce.