Preheat oven 200 °C.Ensure camembert is room temperature. Unwrap and put them back into wooden box. Make sure you put flat side as the bottom in box. Make cross cut in top of cheeses. Cook in oven for 10 min. Spoon plum jam and onion relish together, mix. Remove cheese from oven, carefully fold back the four sides of each cheese, add 2 tsp of plum/relish mix into each cheese, bake for further 10 min.