Remove chicken from the refrigerator, pat dry with paper towels, spatchcock by removing the backbone and press down on the breastbone to lay chicken flat.
Drizzle the chicken on all sides with olive oil. Season with sea salt, black pepper, garlic powder and rosemary. Rub oil and seasoning on all sides of the chicken.
Place the chicken rib side down into a 12 inch cast iron skillet.
Place potatoes, carrots, onions, and brussels sprouts all around the chicken in the pan. Drizzle the vegetables with more olive oil and seasonings.
Squeeze lemon juice and lemon zest over the chicken and place lemon halves in the pan with the vegetables. Place rosemary sprigs in the pan.
Cook the chicken for 45 minutes to 1 hour, until the chicken reaches 160º F in the thickest part of the breast.
Remove from the oven and rest for 10-20 minutes before slicing the chicken.
Notes
Nutrition facts are just an estimate of the ingredients used and are provided as a courtesy
To slice the chicken, slice off the legs at the thigh bone, then remove the wings. Slice the chicken breasts off along the breastbone of the chicken.
To store leftover chicken, place in an airtight container or zip-top bag and place in the refrigerator for up to 4 days.