Prepare the marinade for the chicken by whisking together 2 tablespoons of olive oil, mustard, 2 teaspoons of minced garlic, ½ teaspoon kosher salt, and ½ tablespoon of minced garlic in a large mixing bowl. Add the chicken thighs and toss to liberally coat the chicken in the marinade. Cover with plastic wrap and refrigerate to marinade for 30 minutes or overnight.
When ready to bake the chicken, preheat oven to 400℉.
Place the potatoes and Brussels sprouts in the center of a large-rimmed baking sheet. Drizzle the potatoes with the remaining 2 tablespoons of oil and season with the remaining 1 teaspoon of kosher salt, pepper, 1 teaspoon of garlic, and ½ tablespoon of rosemary. Toss to coat.
Remove the chicken from the marinade and nestle the chicken thighs in between the vegetables, spreading the vegetables to the sides of the sheet pan.
Roast for 35-40 minutes or until chicken reaches 162-165℉ on a digital meat thermometer and the potatoes are fork-tender.
Remove the sheet pan from the oven and let rest for 5 to 10 minutes before serving. If desired, drizzle the juice of a fresh lemon over the chicken and veggies.
Video
Notes
Chicken: Bone-in chicken legs, breasts, and thighs all work in this sheet pan chicken dinner. You can opt to leave the skin on or off. Do NOT use boneless chicken, as the meat will dry out before the vegetables get caramelized.Vegetables: Interchange the potatoes and Brussels sprouts for any hearty vegetable you like--sweet potato chunks, cubed russet potatoes, fresh broccoli, carrots. Just have all the vegetables be approximately the same size so they roast at the same rate (I recommend 1-½ to 2-inch chunks for all vegetables.)Rosemary: If you don't have fresh rosemary, use 2 teaspoons of dried rosemary.Storage: Place leftover chicken and vegetables in an airtight container once cooled slightly. Store in the refrigerator for up to 3 days. Reheat by broiling, microwaving, or baking at 350 degrees F for 15 minutes.