These burgers have an irresistible umami flavor profile, and great texture. Absolutely scrumptious!
In a large skillet (use largest you have) over high heat, add the balsamic vinegar, mushrooms, and pepper. Cook, stirring only occasionally, until the mushrooms have started to brown and shrink down (9 to 10 minutes). Push most of the mushrooms to the outer edges of the skillet (creating a well in the center), turn the heat down to medium or medium-low, and add the onion and salt. Cook for a couple of minutes, then add the garlic (adding the garlic later helps prevent it from burning). Stir the mushrooms into the onion mixture and cook for another 6 to 7 minutes, until the onion is softened and translucent. Add the 1 tablespoon of the balsamic vinegar to the pan, stir, and then remove from the heat. In a food processor, combine about three-quarters of the mushroom mixture with the tahini, miso, sage, oregano, tamari, oats, fresh parsley, and Worcestershire sauce (if using). Process until it just comes together. Add the pecans, pulse once or twice (to break up but not fully process), and then add the remaining mushroom mixture, pulsing once or twice just to incorporate. Remove the blade, and shape mounds of the mixture into patties with your hands (yielding six, or five larger patties). The patties can be refrigerated or cooked immediately. To cook, place on a nonstick skillet over medium or medium-high heat and cook the patties for 6 to 8 minutes, then flip and cook for another 4 to 5 minutes until a golden sear has formed on each side, working in batches, if necessary. (To oven-bake, place patties on baking sheet lined with parchment paper. Bake at 400 degrees, for roughly 10 minutes on one side, then flipping and baking another 10 minutes.) Serve up! Makes 5 to 6 patties.