Equipment
Ingredients
Duck
- 2 duck breasts, skin on
- 5 g sea salt
- 2 g black pepper, freshly cracked
Duck Fat Potatoes
- 400 g baby potatoes, halved
- 3 g fresh rosemary, leaves stripped and finely chopped
- 3 g flaky sea salt
Kumquat à l'Orange Sauce
- 30 g granulated sugar
- 30 ml white wine vinegar
- 120 ml fresh orange juice
- 5 g orange zest, finely grated
- 120 ml chicken stock
- 100 g kumquats, thinly sliced, seeds meticulously removed
- 15 ml grand marnier
- 15 g unsalted butter, very cold and diced
Nutrition (per serving)
Method
Preheat the oven to 200°C (400°F) in preparation for roasting the potatoes.
Using a chef's knife, score the duck breast skin in a tight crosshatch pattern, ensuring you do not pierce the red meat underneath. Season generously with sea salt and black pepper. Wash your hands and the cutting board thoroughly after handling the raw poultry to prevent cross-contamination.
Place the halved baby potatoes in a medium pot of salted water. Bring to a boil and cook for 10 minutes until just fork-tender, then drain well.
Place the scored duck breasts skin-side down in a cold heavy skillet. Turn the heat to medium-low and cook for 12 to 15 minutes to slowly render the fat and crisp the skin.
Pour 30ml of the rendered duck fat from the heavy skillet into a roasting pan. Add the boiled potatoes and fresh rosemary, tossing vigorously to coat and rough up the potato edges. Roast in the oven for 30 minutes until golden and crisp.
Flip the duck breasts in the heavy skillet, increase the heat to medium, and cook the flesh side for 3 to 5 minutes until the internal temperature reaches 54°C (130°F) for a medium-rare finish, or up to 74°C (165°F) for fully cooked depending on safety preferences.
Transfer the cooked duck breasts to a clean cutting board and let them rest for 10 minutes. This allows the muscle fibers to relax and redistribute the savory juices.
While the duck rests, begin the gastrique. In a small saucepan, combine the granulated sugar and white wine vinegar over medium heat. Swirl gently until it cooks into a bubbling, deep amber caramel.
Carefully pour the fresh orange juice, orange zest, and grand marnier into the caramel. Stand back as it will sputter and seize into a hard mass. Simmer gently until the hardened sugar dissolves completely into the liquid.
Pour the chicken stock and sliced kumquats into the small saucepan. Simmer for 6 to 8 minutes until the liquid reduces heavily into a thick, syrupy consistency.
Remove the small saucepan from the heat. Gently whisk in the cold diced butter until it is fully incorporated, transforming the reduction into a velvety, emulsified sauce.
Using a chef's knife, slice the rested duck breasts against the grain into neat, even medallions.
Arrange the duck slices and hot roasted potatoes on warm plates. Spoon the syrupy kumquat and orange glaze generously over the duck, finishing with a pinch of flaky sea salt on the potatoes.
Chef's Notes
- Slicing the kumquats thinly and meticulously removing the hidden seeds is absolutely vital, as the seeds impart a sharp, aggressive bitterness that will completely overpower the delicate sauce.
- A cold-pan start is the secret to perfectly rendered duck breasts. Applying gradual heat prevents the skin from seizing, allowing the thick layer of subcutaneous fat to melt away evenly while creating an impossibly crisp crust.
- Parboiling the baby potatoes and deliberately roughing up their edges in the pot creates a starchy outer slurry. When introduced to the rich, hot duck fat, this slurry roasts into a magnificent, glass-like crunch.
- Mounting the sauce with cold butter off the heat, a technique known as monter au beurre, rounds out the sharp acidity of the vinegar and citrus while creating a brilliantly glossy, luxurious mouthfeel.
Storage
Refrigerator: 3 days — Store duck, potatoes, and sauce in separate airtight containers.
Reheating: Reheat the duck and potatoes gently in a 175°C (350°F) oven until warm. Reheat the sauce gently on the stovetop over low heat, whisking constantly to maintain the emulsion.
