Poach the pitted fresh tart cherries in white wine for 8 minutes. Strain the juice from the poached cherries. Reduce the poaching liquid to the syrupy stage. Reserve
Place the rendered fat into a frying pan and fry the potatoes over medium heat, turning them from time to time until they are golden brown.
Add the leeks to the potatoes and cover with a lid. Reduce heat and continue to cook for approximately 10 minutes or until the leeks are nicely wilted and the potatoes are tender. Remove lid and reserve.
Season the duck breast with salt and pepper and sear on both sides over high heat.
Reduce temperature to low and continue to cook the breast on the skin side for a further 5 minutes or until the skin is a deep brown colour and crisp consistency.
Place in the oven at 325⁰ F (400⁰C) for a further 10 minutes. Remove and transfer breasts to a carving board.
Spoon the potato and leek mixture onto 4 heated dinner plates.
Carve the duck breast and place an equal number of slices in a leasing fan pattern on each of the four plates.
Combine the syrupy cherry juice with the poached tart cherries and spoon this mixture over the duck breast slices. Serve right away.