Put the unskinned onions in boiling water for about 5 minutes. Remove and cool. Cut of tops, peel, and scoop out the insides. Chop the insides of onions. Set aside.
In frying pan cook bacon until crisp. Drain off fat, add butter and saute the bacon bits, chopped onion, and the chopped cloves of garlic until just lightly brown. Add the water chestnuts and bread crumbs and continue to brown for another 3 minutes. Add salt and pepper.
Fill each onion with the mixture. Place in casserole. Pour apple cider over and bake at 375 degrees for 45 to 50 minutes.