Combine the brown sugar and seasonings in a small bowl. Sprinkle half of the mix onto both sides of the chuck roast - save the remaining half of the seasoning mix for later.
¼ cup brown sugar, 2 tablespoon chipotle chili powder, 1 tablespoon paprika, 2 teaspoon onion powder, 2 teaspoon dried oregano, 2 teaspoon kosher salt, 1 teaspoon garlic powder, ½ teaspoon pepper, 3-4 lb chuck roast
Heat a large skillet over high heat with 2 tablespoon of the oil. Once hot, sear each side of roast for 2-3 minutes until a golden brown crust is formed. Remove and place in a 6 qt or larger slow cooker.
3 tablespoon olive oil
Turn the empty skillet to medium heat. Add the remaining 1 tablespoon olive oil. Add the onion and saute for 3 minutes, stirring often. Then add the garlic and saute for 1 minute. Add the beef broth, remaining seasoning mixture, and can of tomatoes. Simmer for about 1 minute, scraping any brown bits off the bottom.
1 medium yellow or sweet onion, 2 tablespoon garlic, 14-15 oz can beef broth, 14.5 oz can fire roasted diced tomatoes
Pour the broth and tomato mixture over the roast in the slow cooker. Cook on low for 8-10 hours or high for 4-4.5 hours, or until it falls apart easily when prodded with tongs or forks.
Once ready, use tongs to move it onto a cutting board. Use two forks to gently remove any large chunks of fat. Then use the forks to pull the meat apart into bite sized shreds.
Strain the chunky bits out of the remaining cooking liquids, then stir the meat and liquids back together in the slow cooker. Serve as tacos, bowls, or salads with your toppings of choice.
12-18 corn or flour tortillas, Lettuce, tomato, shredded cheese, salsa, sour cream, avocado, Rice or beans