I usually add potatoes ( good for 'stretching' to feed a family I found.) Also, for the vegetarian options, Eggplant makes a wonderful alternative to ground beef or 'Minced beef' as us Brits know it. Use it minced up as you would use beef in Lasagne, spaghetti bolignaise, shepherds/cottage pie etc. Cook meal as normal and then freeze as meals for the future.
Life is like good wine.......best taken with friends x