Directions

1. In a 2-quart saucepan, heat the potatoes and enough water to cover to boiling over high heat.  Reduce the heat, cover and cook for 20 minutes.
2. Meanwhile,  heat the oven to 350F. Lightly grease the center of 12-inch ovenproof platter.
3. In a food processor process 2 slices of wheat bread into crumbs. In a large bowl, mix together the bread crumbs, chicken, egg whites, 1/2 teaspoon salt and pepper until well combined.
4. Process the remains bread slices in the food processor, 1/2 cup white mushrooms, parsley, and green onions until finely chopped.
5. On a piece of wax paper, pat out the chicken mixture to an 8-inch square. Pat the mushroom mixture  into in even layer on the chicken. Roll it up in a jelly roll fashion using the wax paper for support. Lift onto the platter and take of the wax paper. Bake in the oven for 20 minutes.
6. Meanwhile, in a small saucepan, sauté the garlic in 1 tablespoon of butter over medium low heat until lightly browned. Remove from the heat and stir in the milk. When the potatoes are tender, drain and discard the water. In the same saucepan, using a hand-held electric mixer beat in the potatoes. Add 1/2 teaspoon of salt, half the milk mixture and egg-yolk. Gradually beat in the remaining milk mixture, until fluffy.
7. Remove the loaf from the oven and evenly cover with mashed potatoes. Place bak in the oven and bake for another 30 minutes or until golden brown.
8. meanwhile, in a large skillet, melt the remaining butter. Add the remaining white mushrooms and wild mushrooms, and sauté until tender. Arrange the mushrooms around the loaf.