-
Preheat oven to 400 degrees F. Drain any juices from chicken and set in a 9-inch cast iron skillet, baking dish, or small roasting pan. Tuck lemon halves next to the chicken. Set aside.
-
Set potatoes in a large pot of cold water and bring to a boil. Add 2 tablespoons sea salt. Boil 12 - 15 minutes or until potatoes are fork tender. Drain and set aside to cool.
-
Arrange potatoes on a large rimmed baking sheet. Using a flat-bottomed cup or a small pan, smash potatoes so they split open. Use a paring knife to make a 1-inch deep cross cut in the top, and if needed, smash a bit more to expose the surface area of the potato. Brush generously with melted butter, sprinkle with sea salt and pepper.
-
Roast chicken and potatoes for 20 minutes. Push potatoes to one side of the pan; arrange Brussels sprouts on the other side. Brush potatoes and Brussels sprouts with remaining butter, and sprinkle sprouts with sea salt and pepper. Roast 15 - 20 minutes more, or until the chicken reaches an internal temperature of 165 degrees F and the potatoes and sprouts are cooked through with crispy edges.
-
Rest chicken 5 minutes, then carve. Squeeze juice from roasted lemon halves over the chicken and Brussels sprouts, and then serve right away.