Duck Burgers with Pickled Fennel and Prune Mayonnaise

Ingredients

• 2 1/2-pound duck breasts
• 2 teaspoons whole grain mustard
• 1 tablespoon sliced chives, plus extra for stacking on the burger
• Kosher salt and freshly ground black pepper
• 3 soft pitted prunes, plus a few extra for garnish
• 1/4 cup mayonnaise
• 2 brioche or other buns, halved horizontally and lightly toasted
• 4 leaves gem or green leaf lettuce
• 1 recipes Quick Pickled Fennel, or other pickles as desired
• Cornichons, to serve alongside

Directions

1. Pull the skin off the duck breasts and set the skins aside, then cut the duck breast meat into rough pieces. Put the meat in a food processor with the mustard and chives, and season with salt and pepper. Pulse in short bursts until the duck is coarsely ground, about 15 to 20 pulses. Shape the mixture into two patties about 4-inches across, pressing a shallow indentation into the middle of each.
2. Put one duck skin in a medium nonstick skillet over medium heat, saving the second duck skin for another use or throwing it away. Cook the skin so the fat melts into the pan, turning and moving it around now and then. Once the skillet has a good coating of duck fat, remove the remaining skin and either discard it or eat it. Warm the fat until it shimmers, then add the patties. Cook them, turning from time to time, until they reach your preferred doneness, about 130 degrees F for medium rare or 140 degrees F for medium.
3. As the burgers cook, prepare the prune mayonnaise. Wash out the food processor, then add the prunes and mayonnaise. Process until smooth, thinning with 1 to 2 tablespoons of water if needed.
4. Spoon prune mayo onto the bottom halves of the buns. Layer on the lettuce, cooked burgers, pickled fennel, snipped chives, more mayo, chopped prunes, and the top buns. Serve with cornichons alongside.