Prepare the sauce: mix mayonnaise, garlic and soy sauce in the required proportions. Grate the cheese.
Separate one flap of the mussel shell and place the resulting sauce on the other with a cap. Sprinkle grated cheese on top.
Place in an oven preheated to 180 degrees for just a few minutes until the cheese is browned.
Before serving, you can sprinkle with lemon juice; it goes very well with wine. An ideal and quick snack for a romantic evening.