Turn the Instant Pot to the Saute setting, and add the olive oil and butter.  When the butter melts, add the chopped onion, and cook until it caramelizes, or is golden brown (about 5 minutes). 

 Add the minced garlic, and cook 1 - 2 minutes. Turn off the Instant Pot. Add the tomato sauce, the stewed tomatoes, the tomato paste, and 1 1/2 cups of bottled water. 

Add all spices, and stir well, making sure to scrape the bottom of the stainless steel liner to the Instant Pot, to loosen any onion or garlic. Stir until all ingredients are well blended.  Add the lid to the Instant Pot, set to sealing. Press the manual button and set the timer to '30' minutes. Release pressure naturally.

Allow to cool, and pour into a covered container, or into glass jars. If you're using jars, you'll need more than 1 or 2, depending on how large the jars are. If they're 16 ounce jars, you may need 4 or more. Refrigerate the sauce up to 7 days. You can freeze the sauce for later use, up to 4 months. 

MEATBALLS: You'll need a large bowl, a large piece of waxed paper or foil to put the meatballs on, a Ziploc bag, and a large spoon. In a large bowl, combine the sirloin and ground round, and mix well.

 Add all ingredients, except for the crushed Ritz crackers, adding those last. Blend altogether, using clean hands, and roll in balls, about 2 inch balls, and lay on waxed paper or foil. 

Add the flour to the Ziploc bag and set aside. When you're done rolling the meatballs into balls, and washed the tomato sauce from the Instant Pot liner, place about 10 of the meatballs in the Ziploc bag, and shake gently to coat the meatball in the flour. 

Turn the Instant Pot to 'SAUTE', and add the olive oil and butter. Working in small batches, when the butter melts, add the meatballs from the Ziploc bag to the Pot, and brown on all sides, about 10 minutes (I used a curved fish spatula to turn the meatballs). When they're browned, and done in the middle, remove them to a plate, and set aside, and continue to coat the meatballs in the flour and brown and cook until all meatballs are done. When the meatballs are all cooked. Turn the Instant pot off. 

Add 1 1/2 cups of water to the Pot, stir and scrape the bits that may be stuck on the bottom of the pot, until they're loosened. Add about 1/2 cup of the tomato sauce to the water, and stir well. 

Open the package of Spaghetti, and break it in half, and add it to the Instant Pot, placing it in the water, and stir well to cover Spaghetti as much as possible. Place meatballs on top of Spaghetti, and cover meatballs in tomato sauce, about 1 1/2 cups. Place lid on Instant Pot until it beeps and locks, and make sure the Pressure Valve is set to SEALING. Press the manual button, and set the time to 6 minutes. 

Allow the Instant Pot to build and release pressure automatically. When Instant Pot is done, make sure pressure button is down, and turn valve to 'VENTING' to make sure all pressure has been released. 

Remove lid to Instant Pot, and with a large utensil, such as a large spoon, remove the meatballs to a platter. Remove the Spaghetti to the same platter. Stir the Sauce in the Pot, and add additional sauce to the Pot and Saute for 4 or 5 minutes, until the sauce thickens.

 Ladle the Sauce over the Spaghetti and meatballs. Serve immediately. Enjoy!