01 - Place chicken breasts or thighs in the bottom of the slow cooker.
02 - Add diced onion, minced garlic, jalapeños if using, and pour diced tomatoes with juices over the chicken.
03 - Sprinkle chili powder, cumin, smoked paprika, oregano, salt, and black pepper evenly over all ingredients.
04 - Pour chicken broth into the slow cooker.
05 - Cover and cook on low for 6 hours or on high for 3 hours, until chicken is very tender and easily shreds with a fork.
06 - Remove chicken from slow cooker, shred using two forks, return to the sauce, add lime juice, and stir to combine.
07 - Warm tortillas according to package instructions.
08 - Spoon shredded chicken onto warm tortillas, add favorite toppings, and serve with lime wedges.