The chicken should be cooked through by the time you finish the Brussels sprouts, so about 15 minutes. Since the thighs can vary in size and thickness, you may need a bit less or a bit more time, so check them with a thermometer (they should be 165F when finished) or by cutting one open at the thickest part.
How long does the chicken need to finish cooking in the oven?
The chicken should be cooked through by the time you finish the Brussels sprouts, so about 15 minutes. Since the thighs can vary in size and thickness, you may need a bit less or a bit more time, so check them with a thermometer (they should be 165F when finished) or by cutting one open at the thickest part.