Roasted Spatchcock Chicken : One pan easy comfort dinner!

5lb Whole young chicken Salt and pepper Marinade 1 Tbs Italian seasoning 1Tsp Paprika 1/2 Tsp Chili powder 1 Tsp Oregano 2 Tbs Balsamic vinegar 1 Tbs Worcestershire sauce 4 Tbs Olive oil 1 Lemon zested and juiced 2 Tbs Parsley, chopped plus more for garnish For the vegetables 5 Yukon gold potatoes 1 Yellow onion 2 Medium carrots, peeled , diced medium 15 Brussel sprouts ( about 1/2lb ) 1 Lemon, sliced