Heat oven and bake the flatbread bare for about 10 minutes. Heat olive oil in a skillet and add diced onion. Cook until almost brown. Add a little water and sugar and cook until pan is dry again. Spread fig jam on warm flatbread, top with cheeses, onion, proscuitto. Bake in oven until cheese is melted. Top with arugula and a drizzle of olive oil. Cut into pieces. Other good toppings are toasted walnuts, crushed red peppers, and sliced apples.