1. Pipe the edges of buttered large scallop shells with the duchesse potato using a fancy tube, sprinkle with melted butter and dry lightly under a salamander grill without coloration.
2. Pour a little of the Mornay Sauce in the bottom of the shells, place the hot sliced scallops and tongues on top and coat with more Mornay Sauce.
3. Sprinkle with grated Parmesan cheese and melted butter and glaze the sauce and potato under a salamander grill.
4. Serve on a flat dish on a dish paper with picked parsley.