Sauté onions in 2 Tbsp butter in a large skillet. Add lamb and sauté for 3-5 minutes. Stir in all seasonings and 1 Tbsp flour.
Add wine and cook, stirring constantly, for 2 minutes. Remove from heat and cool.
Separate 2 of the eggs. Beat 2 egg yolks with 2 Tbsp cream and stir into the meat mixture. Beat egg whites until stiff and fold into the meat mixture.
Heat 3 Tbsp butter in large skillet. Add potatoes and cook, turning several times, for 10 minutes.
Cover and cook on low for 10 minutes longer.
Butter a 10 cup baking dish with remaining butter. Sprinkle with bread crumbs. Layer meat mixture and potatoes at least twice, ending with potatoes.
Bake, uncovered, at 350° F for 30 minutes.
Beat remaining flour, cream and egg together in a small bowl. Pour over top of casserole and bake 10 minutes longer.
Servings: 6