Prepare the shallots. Peel and cut pole to pole in ¼ inch strips. Separate the layers.

Prepare the duck breasts. Pat dry and place skin side up on a cutting board. Using a very sharp knife, score the skin in a crosshatch without cutting into the meat. Undercutting is better than overcutting. Place the duck breasts skin side down in a cold 12-inch pan. Using medium heat, begin to render the fat from the skin. Leave the breasts alone until fat begins to collect around them, about five minutes. If the breasts release, check the color of the skin.

Adjust the temperature lower if the skin has begun to brown. After about eight minutes the duck breasts should render about 6 ounces of fat and the skin should be a light golden color but the meat should be uncooked. Remove the duck to a cutting board and reserve the fat. Sprinkle salt, pepper, garlic powder, and five-spice powder on the meat.

Using a sous vide stick, heat a pot of water to 128°F. Take the duck breasts and vacuum seal them in two bags by putting two breasts in each, with the meat facing each other and the skins on the outside. Alternately, using quart freezer bags and placing the breasts next to each other, immerse them by slowly squeezing the air out as you lower the bags into the water until sealing the bags with as little air in them as possible. Keep the sealed top out of the water with a clip. Do not let the water get into the bags.Cook for one to two hours.

While the duck cooks, prepare the cherry sauce. Empty the preserves in a small saucepot over low heat. When preserves begin to bubble, add the brandy if using and stir to combine. Add vinegar, salt, and water and stir together. Reduce the sauce until it reaches one cup with a thick syrupy consistency. Set aside over low heat. If the sauce gets too thick, add more water. It should drip off a spoon. Thinner is better than thicker.

Reheat the sauté pan over medium-high heat. Remove the breasts from the sous vide bath and cut them out of the bags. Pat dry and place them skin side down in the pan for two minutes to crisp the skin. A little more fat will render. The skins should become golden brown. Remove them from the pan and reserve them.

Add 2 ounces of the rendered duck fat to the pan and the shallots. Sauté the shallots over medium heat until caramelized, brown, and crisp, about three minutes.

Cut the duck breasts into 1-inch medallions. On a plate, spoon two tablespoons of the cherry sauce in an arc. Place the medallions over the sauce slightly overlapping them. Sprinkle the shallots over top and serve.