Spread the duck carcasses on an oven tray and toast them at 200 °C for about 45 minutes. You want a lovely golden color all around.
Once that’s done place them in a big pot. The fat that’s left in the tray you can pass through a fine sieve and keep for later. This is great for pan frying or to confit.
Now pour half a liter of water on the tray and let it soak in the oven for a couple of minutes. This will help to release all those delicious flavors.
Now pour the water in the pan and submerge the duck bones completely with cold water.
Bring this to a simmer on a medium high heat and skim any foam or protein off with a ladle.
Meanwhile we can cut the vegetables. Cut the onions in half and clean them. Then slice them in thin slices, you’ll need 700 grams. Now cut the carrot in half and slice it as well. Do the same with the celery. Then slice the leek in half and wash it well. Now cut it in thin slices.
When the water is at a simmer add the cut vegetables together with the garlic that’s cut in half, the bay leaves, the coriander seeds, the black pepper, the white wine and the white port. Let this simmer on a low heat for at least 8 hours. If needed add a bit more water to ensure all ingredients stay submerged.Â
After that pass the sauce through a fine sieve and let it drip for at least 30 minutes to be sure you don’t waste a single drop.
Bring it to a simmer once more and let it reduce for at least 2/3. While it’s reducing remove any fat or protein that’s floating on top. This will ensure a clear end result.
Once you’re happy with the flavor while stirring add a couple cubes of cold butter. This will thicken the sauce and give a creamy flavor.
I also added a drizzle of sherry vinegar to balance the flavors and make the sauce a touch lighter. Then pass the sauce through a fine sieve once more and keep it in your fridge for later.
