To make turkey carinas: Heat the oil (or drippings) in a large nonstick or cast iron skilled, over medium high heat, until shimmering. Add the shredded turkey, spreading into a single layer, and cook without stirring, for about 5 minutes or until browned and crispy. Stir and continue cooking until the turkey carnitas as as crisp as you like. Season with salt and reserve.
To make the cranberry sauce salsa: Combine the chopped onion, garlic, tomatoes, jalapeño, cranberry sauce, lime juice and zest and cilantro in a medium bowl. Season with salt and reserve.
Preheat oven to 400F degrees.
Spread half of the chips on a large cast iron, oven proof dish or baking sheet. Add half the turkey carnitas, Brussels sprouts (if using), ½ cup of cheddar and ½ cup of Monterey Jack. Top with the remaining chips, turkey carnitas, cheese and Brussels sprouts. Bake until the cheese is melted and chips are toasted, about 10 minutes.
Top with the cranberry sauce salsa, sliced jalapeños, cilantro and a dollop of sour cream. Serve immediately, squeezing some lime juice on top if desired.