Season all sides of your roast with salt and pepper (easy on the salt, pressure cookers enhance the salt flavor so you don't need that much)
Add your cooking fat (we prefer bacon fat) to the instant pot and hit the saute button and adjust so it's on high
After about 2 minutes, add your roast and brown for 3-4 minutes on each side
Remove your meat from the instant pot to your cutting board and hit cancel on the instant pot
Cut your roast into 1-2 inch cubes and place them back in the instant pot
Add your full jar of marinara sauce, place the lid on the pot ensuring it's locked and the pressure valve is closed
Press the meat/stew button and adjust it to 40 minutes, now go do something fun
Once your roast is finished cooking your instant pot will switch to warm, hit cancel to turn it off and allow the pressure to release naturally (about 15 minutes)
Remove the lid and shred all of your beef inside the instant pot using two forks or our shredding hack
You can serve as is or thicken as we prefer
To Thicken
Leave the lid off your instant pot, cover with a splatter screen, and hit the saute button and adjust it to low
Allow the sauce to reduce by at least a 1/4 or to your liking. Ours was on saute for 15 minutes and was perfect
Enjoy
Notes
If you want to cook in the crockpot, still saute the roast in a cast iron skillet or pan if possible and then cook on low for 8-10 hours or high for 4-6 hours.