Heat a skillet over medium. Add walnuts and toast, stirring frequently, until fragrant and golden, about 5 to 7 minutes. Set the walnuts aside to col.
Add the mushrooms to a pan heated to medium with a pinch of salt and a couple of tablespoons of water--just enough to prevent burning. Let the mushrooms cook for about 5-10 minutes to release their water.
Remove the mushrooms from the pan to drain, then heat up about 2 tbs oil in the pan. Return the mushrooms to the pan and this time toss in the onion as well. Let those cook together for about 5 to 7 minutes. Then remove from heat to let cool.
Add the walnuts to a food processor along with the garlic, chili powder, cumin, smoked paprika, and cayenne. Process until you get a fine meal, then transfer to a mixing bowl.
Purée the mushroom mix in the food processor, working in batches as needed, until it is mostly smooth. Add this to the mixing bowl as well.
Toss in the cooked quinoa, Worcestershire sauce, and breadcrumbs. Mix thoroughly, then cover and refrigerate for 1 hour. This helps everything bind together.
Remove the mix from the fridge and let come to room temperature (this helps get rid of extra moisture from the fridge), then form into five patties.
Sauté on a medium skillet until browned on the outside and warmed through, or bake in a 375 F oven for about 12 minutes.