Score the duck breast and seal fat side first without adding any oil, once its well sealed remove from the pan and add the sliced red onion, garlic, spice and sugar, caramelize than add the grapes cut in halves, toss than pour in the wine and simmer until sauce in well thickened. Peel and slice the potato in very thin slices, mix well in a bowl with the cream, cornflower, thyme, seasoning and half the cheese. place in a small oven tray, sprinkle with the cheese left and bake until potato is cooked through and golden brown from top. allow to rest once cooked before cutting using a round cutter or a sharp knife. Slice the courgette on sauté in salted butter, serve on the side of the potato gratin with the grape compote underneath the sliced duck.