Trim the fat from the 4.8 pounds Angus Sirloin Tip Roast (or chuck roast) and cut it into six (6) roughly equal-sized pieces. Using paper towels, pat the meat dry and season with 2 teaspoons of kosher salt and 1 teaspoon of freshly cracked black peppercorns.

Sear the Meat: Select the Saute setting on the Instant Pot and remove the lid. Add 1 1/2 tablespoons of canola or vegetable oil to the pot. When the oil is hot, brown three pieces of the beef, using tongs to move the meat around to get an evenly seared surface.

Remove the browned pieces of meat and place them into a bowl. Add the remaining 1 1/2 tablespoons of canola or vegetable oil and brown the remaining pieces.

Place all the pieces of beef into the Instant Pot and tuck 3 bay leaves between the pieces of meat.

Mix the 1 medium yellow onion (finely diced) in a separate bowl with 1 cup of beef broth and pour the mixture over the meat.

Into a food processor, add 4-5 chipotle chilies in adobo sauce, 1 1/2 tablespoons ground cumin, 1 tablespoon Mexican chili powder, 1/3 teaspoon ground clove, 8 garlic cloves (minced), 1 tablespoon dried oregano, and the remaining 1/3 cup of beef broth. Pulse until the mixture is smooth.

Pour the sauce over the beef, using the back of a spoon to spread it evenly over the meat.

Place the lid on the Instant Pot and lock it into place. Select the Slow Cooking option and cook on low for 8-9 hours.

Vent the Instant Pot and remove the lid. Use tongs to discard the 3 bay leaves.

Mix the meat directly in the pot using two forks to shred it directly with the sauce.

Let the shredded beef rest in the sauce for 10-15 minutes to absorb additional flavor.