What i usually do is - I mix them all and place them in the baking pan and set aside .
All we need is :
Mix the chicken masala, salt , kasoori methi into the yogurt and add the mustard oil & the barbeque sauce.
Slit the chicken drumstick, leaving the skin on is optional - I have tried both ways and it tastes better with the skin on. Coat the marinade on the drumsticks and toss the cubed potatoes in it.
Line the baking pan with an Aluminum foil and place the drumsticks - fit in the potato cubes, place the cubed onions in the available space and do the same with garlic as shown in the pic.Remember , do not peel garlic.
Serve hot with rotis or bread and garlic sauce.