2) If using a charcoal grill, place the drumsticks on the grill and cook until golden brown on all sides.
3) Move the drumsticks to the cooler part of the grill, place the lid on and continue cooking until just cooked through, about 45 minutes to 1 hour, brushing with the glaze during the last 20 minutes of cooking.
4) Remove the drumsticks from the grill, brush with more of the glaze and leave to rest for 10 minutes before serving.
5) If using a gas grill, cook the drumsticks at medium heat the whole time with the lid closed after a crust has formed.
For the sherry vinegar-brown sugar glaze:
1) Heat the oil in a medium saucepan over a medium-high heat. Add the shallots and garlic and cook until a light golden brown. Add the vinegar and cook until reduced by half.
2) Add the sugar, paprika, tomatoes and chicken stock and cook until reduced by half and the tomatoes are very soft. Transfer to a blender and blend until smooth.
3) Return the mixture to the saucepan and cook until thickened; season with salt and pepper. Allow to cool before using.