Heat oven to 450° F. Heat the oil in a large ovenproof skillet over medium-high heat. Season the chicken with ½ teaspoon salt and ¼ teaspoon black pepper. Working in batches, cook the chicken skin-side down until crisp and golden, 6 to 7 minutes. Transfer to a plate; reserve the skillet.
Pour off all but 2 tablespoons of the drippings from the skillet. Add the cauliflower, crushed red pepper flakes, and remaining salt and black pepper; toss to coat. Nestle the chicken skin-side up in the cauliflower, transfer to oven, and roast until the cauliflower is tender and the chicken is cooked through, 20 to 22 minutes.
Add the lime juice and cilantro to the skillet and toss to combine. Serve with the lime wedges.