Slow-Cooker Chipotle Beef Carnitas

Ingredients

2 tablespoons kosher salt
2 tablespoons brown sugar
1 tablespoon ground cumin
1 tablespoon smoked paprika
1 tablespoon chili powder
1 teaspoon garlic powder
1 teaspoon ground mustard
1 teaspoon dried oregano
1 teaspoon cayenne pepper
1 boneless beef chuck roast (3 pounds)
2 large sweet onions, thinly sliced
3 poblano peppers, seeded and thinly sliced
2 chipotle peppers in adobo sauce, finely chopped
3 tablespoons canola oil
16 oz (16 ounces) salsa
16 flour tortillas (8 inches), warmed
3 cups crumbled queso fresco or shredded Monterey Jack cheese
toppings: cubed avocado, sour cream and minced fresh cilantro (optional)

Instructions

Mix the first nine ingredients. Cut roast in half; rub with 1/4 cup spice mixture. Cover and store remaining mixture in a cool, dry place for up to 1 year.
Place onions and peppers in a 4-qt. slow cooker. In a large skillet, heat oil over medium heat. Brown roast on all sides. Transfer meat and drippings to slow cooker. Top with salsa. Cook, covered, on low until meat is tender, 8-10 hours.
Remove roast; shred with two forks. Skim fat from cooking juices. Return meat to slow cooker; heat through. Using a slotted spoon, place 1/2 cup meat mixture on each tortilla. Sprinkle with cheese. Add toppings of your choice.