Eggs on Toast

Make a medium white sauce. Per 2 c. sauce, which will feed 3 or 4 people, melt in about 1/2 c. or to taste) grated Gruyere or Swiss cheese and add a tbsp. of sherry or _shao xing_ and a generous pinch of tarragon. Add black pepper to taste. Keep warm; wrapping pan in a towel usually works well. Saute fresh mushroom caps in a little butter seasoned with a clove of garlic till the juices flow. Pepper these too if desired. Arrange toast on plates, two slices per person. Slice eggs and arrange on toast. Spoon mushrooms and their juices and butter onto eggs. Pour sauce over top, and serve immediately with cold brut champagne and/or good coffee, and fruit or a green salad.