3 tbsp. butter
1 tbsp. minced green-onion tops
1/4 tsp. dried tarragon
Freshly ground pepper
1 egg yolk, beaten
2 tbsp. oil
1 large onion, chopped
8 mushrooms, cut into quarters
1 1/2 lbs. lean leg of lamb, cut into small cubes
3 to 6 tbsp. beef stock
1/4 tsp. Worcestershire sauce
2 tbsp. dry red wine
1/8 tsp. dried tarragon
Scrub potatoes and bake in their skins in a 425°F oven for 45 to 60 minutes, or until tender.
Remove from oven and allow to cool slightly.
Cut potatoes in half and scoop pulp into a large bowl.
Add butter, green onion, tarragon, salt, and pepper and blend well.
Cool to lukewarm, then add egg yolk and beat in thoroughly.
In a large skillet over medium-high heat, heat oil.
Add onion and mushrooms and saute until softened.
Increase heat to high and add lamb cubes.
Saute for 2 minutes.
Stir in beef stock, Worcestershire sauce, red wine, and tarragon.
Remove from heat and add salt and pepper to taste.
Spread about two-thirds of the potato mixture over bottom and sides of a buttered 1 1/2-quart baking dish with deep sides.
Add sauteed lamb and all juices from skillet.
Spread remaining potatoes evenly over top, covering lamb completely.
Dot with butter and bake in a 375°F oven for about 1 hour and 30 minutes, or until top is golden brown and crispy.