This is the recipe I used, for reference (it's from Mark Bittman's How to Cook Everything Vegetarian and was also featured in one of his Minimalist columns from the NY Times).
Time: 20 minutes
1 medium onion
1 cup walnuts, pecans, almonds, cashews or other nuts, preferably raw
1 cup (raw) rolled oats or cooked short-grain white or brown rice
2 tablespoons ketchup, miso, tomato paste, nut butter or tahini
1 teaspoon chili powder or any spice mix you like
Salt and freshly ground black pepper
2 tablespoons peanut oil, extra virgin olive oil or neutral oil, like grapeseed or corn.
1. Grind onion in food processor. Add nuts and oats, and pulse to chop, but not too finely. Add remaining ingredients except oil. Process briefly; don't grind too finely. Add a little liquid -- water, stock, soy sauce, wine, whatever -- if necessary; mixture should be moist but not loose.
2. Let mixture rest a few minutes, then shape it into 4 burgers. (Burger mixture or shaped burgers can be covered tightly and refrigerated for up to a day. Bring back to room temperature before cooking.) Put oil in nonstick or well-seasoned cast iron skillet and turn to medium. When oil is hot, add burgers to skillet. Cook about 5 minutes, undisturbed, until browned, then turn with spatula. Lower heat a bit and cook 3 or 4 minutes more, until firm.