Preparation in advance:
Prepare the ducks. If you choose to use a roasting tin, or roast them on a gridiron, lay them on their back, and drape two slices of bacon over the breast. If the birds are roasted on a spit, bind four slices of bacon around them and use kitchen twine to keep them in place. Don't forget to put a dripping pan under the mallards to collect the drippings.
You can already melt the diced lard for the sauce. The cracklings are delicious to nibble, but very salty. Don't feed them to your pets, however cute they beg for it.

Preparation:
Roast the mallards. To get the typically smokey flavour of a charcoal fire you should use a barbecue, but take care that the drippings do not fall on the coals, because the resulting flames will burn the mallards instead of roasting them. Besides, you'll need the drippings for the sauce. You can also roast the ducks in front of a charcoal fire, as they did in the Middle Ages. The lechefrite or dripping pan was a standard utensil in medieval kitchens.
But you can also roast the birds the modern way, in the oven, at a temperature of 175EC/350EF for 45 to 60 minutes (depending on whether using a convection or conventional oven. Check if the mallards are done, because times vary according to the oven you have, and the birds. They should have a core temperature of 75 to 80EC/165 to 175EF.
Keep the ducks warm while you make the sauce by enveloping them in crinkled kitchen foil (shiny side to the inside).
Prepare the sauce. Fry the onions in the melted lard, add broth, wine and drippings, and pepper and cinnamon. Simmer on a slow fire for fifteen minutes, then finish to taste with mustard(seeds), ginger and salt.

To serve:
The birds were first presented whole, and then cut at the table or the side table: first the legs and wings are cut off, then the breastmeat is lifted from the carcass and cut in sizelable pieces or slices. The carcass is then placed in the middle of a dish, the sliced breastmeat arranged next to it with the wings, the legs are placed behind. By the time the duck was cut and arranged the meat wouldn't be piping hot anymore, which is a good thing if you eat with your fingers.
The sauce can be served in separate sauce boats or poured in the dish on which the mallard is served.