Preheat the oven to 450°F.
Spread the cauliflower, sprouts, and bacon out on a large rimmed baking sheet. Drizzle with oil and season with salt and pepper. Toss to coat well and spread out into a single layer on the pan.
In a small bowl, stir together the melted butter, garlic, cumin, paprika, coriander, cayenne and additional salt and pepper.
Nestle the chicken thighs into the vegetables. Brush the tops of the thighs with the spice mixture.
Bake 30 to 35 minutes, until the center of the chicken thighs registers 165°F on an instant read thermometer.
Turn on the broiler and set the pan on the second highest rack of the oven. Broil 1 to 3 minutes to brown the chicken.
