Important before you start cooking: you will need a baking bag—not a sleeve, specifically a bag!

Also note: the duck should not be an athlete. That is, we are making this dish not with a free-range village duck that loved to fly against the wind but with a pampered duck from a poultry farm.

Finely chop the cherries and keep the juice; if they are frozen, defrost thoroughly and also keep the juice.

Take a baking bag and put the whole duck breast in it, cutting the skin on the breast crosswise (no more than one breast or two halves per bag), cherries, wine, balsamic (if you did not use sherry), spices, salt, and sugar.

Place the bag in a deep bowl of water so that all the air comes out, and tie it tightly so that the duck and sauce components are evenly placed but there is next to no air in the bag.

Take a deep saucepan (at least 5 liters), pour water almost to the top, and put it on high heat. As soon as the water boils, lower in the tied bag with the duck breast so that it is entirely submerged and close the lid completely. Without removing the pan from the burner, turn off the heat and leave for 80-90 minutes.

After this time, remove the bag from the water, dry the outside with a paper towel, carefully cut off the knot (the contents are hot; be very careful!), remove the duck with tongs onto a plate, and pour the juice that has released during the cooking process into a small saucepan. Add a spoonful of starch to this mixture, mix well and heat until it thickens, then puree with an immersion blender until it becomes a sauce. Balance the flavors to your liking.

Dry the duck breast thoroughly with a paper towel and quickly fry in a hot frying pan without oil on both sides to form a golden crust. Cut into slices across the grain and pour over hot sauce. Sprinkle with chopped mint and nuts.

Serve with a green salad, boiled new potatoes, toasted bread, or whatever you like.

There will be some more sous-vide sauces in the next section.