Turn on the oven to 190°C, air circulation, rack at the lowest.
Use an oven proof roasting tin and spread the potatoes, tomatoes and onions. Pour all-over them 200ml of the beer, 100 ml of the oil and sprinkle with half of the salt and pepper.
Take a bowl and add the mustard, honey, thyme, zaatar, sumac, paprika, onion powder, granulated garlic and the remaining 50ml of the oil. Mix well and keep aside.
Pat dry the chicken, place the 2nd beer can in the middle of the roasting tin, can to be opened, and carefully sit the chicken on the beer can through the bottom cavity.
Rub the above mixture all over the chicken while gently massaging and pressing the skin. Season with the remaining salt and pepper and roast for about 90’ and until the bird is nicely charred.
Take off the oven, place the chicken in a plate covered with aluminium foil and arrange the veggies and potatoes in a serving plate. Cut the chicken at your preference and serve in the same plate with the veggies and the potatoes.