Place the fillets into a baking dish, and pour half the sauce over them.
Place the ham slices across the top of the fillets.
Pour the remainder of the sauce over the fillets.
Cut the cheese into slices and place them over the top of the fillets.
Place into the oven at 180 degrees (fan) for 30 minutes.
Cook your chips at the same time according to packet instructions.
Serve with the chips on the plate, and then layer the cooked fillets, sauce, ham, and cheese over the top.