For honey and lavender sauce: bring honey to the boil in a small saucepan over high heat and cook until caramelised (7-8 minutes). Remove from heat. Carefully stir in vinegar and rendered duck fat or oil. Add lavender, season to taste and set aside.
Remove the duck breasts from the refrigerator 10-15 minutes before cooking. Dry with paper towels. Using a very sharp knife, cut incisions through the skin in a crosswise pattern every 2 cm (3/4 in), without cutting into the meat. Set aside. Preheat oven to 200 °C (400°F). Sear duck over medium-heat, skin-side down, until golden and crisp (7-8 minutes). Drain fat as it accumulates. Turn and cook in oven until medium.. Transfer to a warm plate, cover loosely with foil and let rest for 5 minutes.
Season figs with salt, rosemary and a little duck fat. Grill figs under hot grill, cut-side down, until golden (1-2 minutes), then transfer to a serving platter. Top each with a little radicchio and endive. Slice duck breasts and arrange on figs. Drizzle each lightly with honey and lavender drizzle and serve immediately. Finish with a little fleur de sel and micro herbs if desired.