Turn your Instant Pot on the saute setting – high – and cut your chuck roast into large chunks (about the size of your fist). Season the beef liberally with salt and pepper on all sides, and add some olive oil to the Instant Pot.

When hot, add your beef and sear on all sides, adding more oil if the pot gets too dry.

Remove the beef to a plate and add your onion, garlic, crushed tomatoes, Italian seasoning, pepper flakes, and some salt and pepper into the Instant Pot. Stir to combine, and add your beef back into the sauce.

Close the lid, seal the vent, and cook on manual high pressure for 30 minutes. Let the pressure naturally release for 10 minutes before quick releasing the rest.

Remove the beef chunks to a cutting board, and switch the Instant Pot to the saute setting on high. Let the sauce simmer for 15 minutes. Meanwhile, shred your beef into small, bite sized pieces using two forks.

When the fifteen minutes are up, add your shredded beef back into the Instant Pot and, in a separate small bowl, make a slurry with your cornstarch and a few splashes of water (enough to make it a pourable liquid).

Stir your slurry into the sauce and let it thicken – it shouldn’t take long, no more than a minute.

Season to taste with salt and pepper and serve! I like it over pasta, but you could serve it over rice, mashed potatoes, zucchini noodles, cauliflower rice, etc.