This is based on a recipe from Mark Bittman's cookbook, "How to Cook Everything Vegetarian: Simple Meatless Recipes for Great Food". You can choose whatever beans you prefer. When made with chickpeas, they're golden brown and lovely; with black beans, much darker; with red, somewhere in between. Lentils give you a slightly grainy texture. If you start with beans you've cooked yourself-especially well-seasoned ones-the results will be even better. Like almost all veggie burger mixtures, these will hold together a little better if you refrigerate them first (ideally you'd refrigerate both before and after shaping, but that's only if you have the time). If you use the soy flakes rather than rolled oats, it will be higher in protein..