Make stuffing: Cook 3 chopped onions in butter until yellow; add soft bread crumbs, sage, salt, pepper, and parsley. Saute until slightly browned Remove from heat and add 1 egg beaten with 2 Tblsp. water.
Make meatloaf: Combine ground beef, ground pork, 4 slices bread which have been soaked in warm water and drained well. Add 1 chopped onion, salt, pepper and 2 eggs; mix thoroughly. Line bottom and sides of a greased loaf pan with meat mixture. Fill center of pan with onion stuffing. Cover top with remaining meat mixture. Spread with 2 Tblsp. of butter and cover with 1/2 cup chili sauce. Bake in 400* oven for 1 1/2 hours.