Place the oil in a large skillet. Heat on medium-high heat.
Fry the beef until browned on all sides. Drain any excess grease from the beef cubes, then place them into the crockpot.
Pour in the broth, tomatoes, and puttanesca sauce.
Cook on low for 6-8 hours or until the beef is tender and falling apart. Taste test, and if the sauce is too acidic, add in a bit of white sugar to balance out the flavor.
Half an hour before serving, mix in the pasta. Let it cook in the slow cooker soup until it has softened and is ready to eat.
Serve topped with a sprinkle of parmesan cheese if desired!
Instant Pot
Place the oil in the bottom of your instant pot. Use the saute button and fry the beef until browned. Remove any excess grease from frying.
Pour in the broth, tomatoes, and sauce. Deglaze the bottom of the pot by scraping it with a wooden spoon to remove the browned bits.
Cook on high pressure for 60 minutes. Let the pressure release naturally. Taste test, and if the sauce is too acidic, add in a bit of white sugar to balance out the flavor.
Stir in the pasta of choice. Let cook in the hot soup for 20 minutes or until softened. Serve in bowls.
Notes
You can make this in a pot on the stove as well and cook for an hour or two, but there's nothing like beef that falls apart thanks to being cooked all day long.