Heat the oven to 325 degrees. If using toast, cut a hole in the center about the size of an egg yolk. Butter the bread slice and spread it with cottage cheese. Place it in a small baking dish. Break the egg over the hole in the bread slice. Spoon the buttermilk over the egg. Bake until the white is set and the yolk firm but not solid, about 8 minutes. Season with salt and pepper.