Sliced Ham With Egg In The Middle

Sliced Ham With Egg In The Middle - 3/4 lb mushrooms, finely chopped, 1/4 cup finely chopped shallot, 2 tablespoons unsalted butter, 1/2 teaspoon salt, 1/4 teaspoon black pepper, 2 tablespoons creme fraiche or sour cream, 1 tablespoon finely chopped fresh tarragon, 12 slices black forest or virginia ham.