Set Instant Pot to saute. When it says HOT, add oil.
Add ground beef, onions and garlic to pot. Cook until meat is browned, stirring to break up meat. Season with salt, pepper, thyme and Worcestershire sauce as it is cooking.
Add tomato paste, water and beef base. Stir to scrape up any bits stuck to the bottom of the pot. Add elbows. Press cancel to stop Saute.
Lock lid in place and seal valve. Cook on high pressure for 4 minutes. (Cook time may vary with the kind of pasta you choose to use). Quick release the pressure. Stir in half of the cheese. Serve remaining cheese on the side.
These are called Italian Meatballs, but they can be made into just about any kind of meatball you want by changing or leaving out the Parmesan cheese. You can make Swedish Meatballs http://www.cherylsrecipes.net/recipe/swedish-meatballs/, BBQ Meatballs, Sweet & Sour Meatballs, etc. You can even cut small cubes of mozzarella cheese (or any other kind of cheese) and wrap the meatball mixture around it before baking. You will want to make a larger meatball for making them this way, though. Meatballs always make a good dish for a potluck or a party!
Heat a large skillet over medium high heat. Add the oil and brown the ground beef.
As the beef is cooking, slice the mushrooms and add the mushroom slices to the partially cooked ground beef.
Combine the seasonings as that finishes cooking.
Add all other ingredients, except sour cream, to the cooked beef. Stir to combine and cover.
Bring to a boil, then lower heat to medium low and allow to simmer for 10-12 minutes, or until the noodles are cooked through. The time may vary depending on the type of noodles you use. Read the directions on the package. This gluten free Barilla fettuccine takes 13-14 minutes, but white spelt pasta takes 7 minutes!
Add the sour cream and stir. If it is too watery, let sit for 5 more minutes. Serve immediately.
Preheat oven to 400. Line baking sheet with heavy duty foil, then parchment paper. (The foil makes it so you don't have to wash the pan and the parchment paper prevents the meatballs from sticking to the foil.)
Combine all ingredients for meatballs. Using a small cookie scoop, form meatballs and bake on baking sheet for 15 minutes.
While that is baking, put oil in skillet and dice onion. Begin cooking the onions while you slice the mushrooms. Add to onions.
When onions and mushrooms are nearly done, add beef base, black pepper and garlic powder. Add 2 cup of water to the pan. Bring to a boil. Combine cornstarch with remaining 1/2 cup of water. Gradually add cornstarch mix to pan and stir as you are pouring. Cook, stirring often, until thoroughly mixed.
Add cooked meatballs to mushroom sauce, cover with lid and bring to a simmer. Simmer for 30 minutes.
Note that the meatballs will grow when cooking because of the raw rice in them.
Nutrition info on 5 meatballs with sauce: 258 calories, 11 g fat, 81 mg cholesterol, 581 mg sodium, 193 mg potassium, 20 g carbs, 1 g fiber, 2 g sugar, 20 g protein