If you have a day to spare, I recommend you try dry brining the chicken. Simply peel back the skin and rub salt under the skin on the breasts, thighs and legs. Refrigerate overnight. This will result in a crispier and even juicier chicken.
Set oven or fire up your grill to 420F/216C.
Pat the chicken dry with a paper towel.
Mix together the ingredients for the rub. Then massage the chicken under the skin and on top with the rub. Be thorough – Peruvian chicken is very flavorful! Let it marinate at room temperature for 20 – 30 minutes.
Toss the Brussels sprouts and onions in a bowl with olive oil, sea salt and pepper.
Place the chicken on a metal rack set inside of baking tray. This is the ideal set up to capture the juices for gravy and so that the chicken doesn’t cook in oil/fat. Placing the sprouts around the chicken on the rack will also help them to be extra crispy.
Roast for about 40 minutes, or until the internal temperature of the chicken reaches 165F/74C.
If needed, reduce the heat to 400F/204C if you see the veggies burning.
Once the chicken has finished cooking, remove it from the heat then place a tent of foil over it to keep it warm while it rests.
Enjoy with delicious Peruvian aji verde (salsa)!