Carrots Excelsior

Recipe submitted by Judy Hughey
My husband's mother was from Keene, New Hampshire. This is her recipe.
Carrots Excelsior
Ingredients:
2-1/2 c carrots, cooked, mashed, and seasoned with salt and pepper
2 egg yolks, beaten
1-1/2 c milk
1 c bread crumbs
1 T finely chopped onion
2 egg whites
Directions:
Mix all, except egg whites. Beat egg whites stiff and fold lightly into carrot mixture. Turn into buttered 1-1/2 qt. casserole. Bake at 350 degrees for about 45 min.or more, until knife inserted comes out clean. Serve hot. Serves 6-8.