Place all ingredients for the chicken except for the chicken thighs into a medium bowl. Mix well. Add the chicken thighs, making sure they’re well covered with marinade all around. Cover and set aside.
Prep the veggies:
Preheat the oven to 430°F. Cut the sweet potatoes into chunks. Halve the sprouts, cutting larger ones into quarters. Core and thickly slice the apples, peel and thickly slice the red onions. Place all on a sheet pan and drizzle with oil, salt and pepper.
Place the marinated chicken thighs on top of the pepped veggies on the sheet pan. Tuck the fresh herbs all over the pan. Bake for 25-30 minutes, or until the chicken is done all the way through and the Brussels sprouts are tender.