How to Make It
In a large skillet, heat the butter and olive oil over medium-high heat. Season the chicken with salt and black pepper. Add the chicken to the skillet, making sure to not overcrowd the pan. Cook until richly golden brown and seared, about 4 minutes per side. Pour in the white wine and deglaze the pan. Transfer the chicken and the juices to the slow cooker.
Return the skillet to the stove and set over medium heat. Add the onions, garlic, paprika, and chili powder and cook until softened, about 4 minutes. Add the spiced onion mixture to the slow cooker. Pour in the chicken broth and crushed tomatoes and stir to combine. Cover and cook for 2 hours on high or 4 hours on low heat, until chicken is tender.
Remove the chicken from the sauce and transfer to a work surface. Using two forks, shred the meat; discard the bones. Stir the shredded chicken back into the sauce and add the lime juice and chopped cilantro. Season with salt and black pepper to taste.
Using a slotted spoon, spoon the pulled chicken into the warm tortillas and top with shredded cabbage, sour cream, sliced avocado, and cotija cheese. Serve right away.