Preheat the oven to 400˚F. Mix the egg whites and broth in a small bowl. Put bread slices in a large bowl, pour the egg mixture over the slices of bread and let them soak until the liquid is absorbed. Mix in and parsley and meat. Form the mixture into balls of about ½ inch to 1½ inches wide. Brown each meatball on all sides in a nonstick skillet. Bake them for about 15 minutes at 400˚F. Meatballs freeze well, so you can store them frozen for up to a month. Just take one out, thaw in the fridge, or warm it in the microwave.