Salt and pepper both sides of the chuck roast. I had to cut mine into two pieces.
Select the Saute button on your Instant Pot, and add the oil.
Brown the chuck roast on both sides, about 4 minutes per side. Remove the roast to a plate and deglaze the pot with the tomatoes and water. Then place the roast back into the pot.
Add the garlic and onion slices.
Place the lid on the Instant Pot, select the high pressure setting, and set the timer for 75 minutes
The Instant Pot will beep when it is finished. Allow the built up pressure to release naturally, then remove the lid.
Shred the beef with two forks, I place mine on a large dinner plate.
Remove the tomatoes and onions from the pot and return the shredded beef. I strain them but keep some of the juice to moisten the meat with. Add it back into the beef when you put it back into the pot.
Add the lime juice, cumin, chili powder, and cilantro, stir to combine.
Place the lid back on top of the pot until ready to serve. Beef can be used to make tacos, salad, burritos, chimichangas, etc.