It is ridiculously easy to make. Make pastry, line flan tin. Scatter base with rhubarb and sprinkle with sugar. Bake for 20 mins. Make a custard with 3 eggs, crême fraiche and melted butter......do not think of calorific content. Pour onto rhubarb in flan tin. Put back in oven and bake again until puffed and firm.
Cool, trim off excess pastry and present on best white plate.