Slice the onion and sauté in butter with the sugar until caramelized, add the vinegar reduce and remove from heat. Use 2 round stainless steal cutters to cut the pastry than put the same cutters on an oven tray. Place the cooked onions divided in both cutters and than cover with the cut pastry. Remove cutter and brush the pastry with the egg yolk, bake until pastry is golden brown. once cooked remove from heat and use a wide slicer to turn the tart upside down. Peel, boil and dice the beetroot, quarter the mozzarella, chop the chilly and mix all in one bowl with the basil leaves and flaked almonds. Meanwhile cut the peaches in segments and place on an oven tray drizzle with honey and roast until golden brown, allow to cool and mix well with the rest of the salad. Serve the salad on the warm onion tart tatin.