Heat oven to
350F (175C). Butter a 3-qt (4-L) casserole. Melt 6 tbsp butter in medium
saucepan. Add mushroom pieces and cook gently until lightly browned,
stirring. Sprinkle in flour, salt, pepper and chervil and stir to blend.
Remove from heat and add milk all at once. Stir to blend. Return to heat
and cook until boiling, thickened and smooth, stirring constantly. Put
1/3 of the egg slices in the bottom of prepared casserole. Add 1/3 of
the ham cubes and 1/3 of the sauce. Repeat these layers twice more.
Combine bread crumbs and 1/4 cup melted butter. Sprinkle over top. Bake
about 30 minutes or until bubbling well.