Place citrus marinade and chicken breast in a gallon-sized plastic baggie on medium-sized plate. Marinate in the refrigerator for at least 30 minutes or in the refrigerator for up to 8 hours.
Preheat oven to 400°F (200°C).
In a large mixing bowl, combine olive oil and kosher salt. Toss until the potatoes and fennel are fully coated. Transfer to a sheet tray and roast in the oven for 25-30 minutes until brown and crispy.
Light your grill or preheat your charcoal grill.
Lightly grease your grill grates and place your marinated chicken on the grill. Cook for 6-7 minutes, or until there are visible grill marks on both sides and the chicken reaches an internal temperature of 165°F.
Transfer chicken to a plate and loosely cover with foil rest for 5-10 minutes.
In a small mixing bowl, combine citrus gremolata, olive oil, citrus vinaigrette, garlic, and a pinch of kosher salt.
In a mixing bowl, combine greens, citrus vinaigrette, olive oil, and a small pinch of salt.
Plate the roasted potatoes and fennel and drizzle with citrus vinaigrette. Top with grilled chicken-leg each chicken breast with a generous spoonful of gremolata sauce.
