Melt 3 tablespoons of the butter in sauce pan then stir in flour.
Gradually add in milk and cook slowly until thickened, stirring constantly.
Press cooked beans through sieve and combine with sauce.
Season with salt and pepper and mix with beaten eggs.
Pour into greased casserole dish, cover with bread crumbs and dot with remaining butter.
Bake in 375 degree oven about 20 minutes.