Step 1

Heat the olive oil in a medium skillet over medium heat. Add the shallot and sauté until soft, 1 minute. Add the mushrooms, a generous pinch of salt, and sauté until soft and browned, 6 to 9 minutes, turning down the heat slightly, as needed.

Step 2

Stir in the tamari, vinegar, and mirin. Stir, reduce the heat, then add the garlic, and smoked paprika, and sriracha. Remove the pan from the heat and let cool slightly.

Step 3

In a food processor, combine the sautéed mushrooms, walnuts, flaxseed, brown rice, and ½ cup of the panko. Pulse until well combined.

Step 4

Transfer to a large bowl and stir in the remaining panko.

Step 5

Form into 8 slider-sized patties or 6 burger-sized patties.

Step 6

Preheat a grill to medium-high heat. Spray the grill with nonstick cooking spray and drizzle or brush the patties with olive oil. Grill for 4 to 5 minutes per side, or until char marks form. Remove from the grill, brush with Worcestershire sauce, and serve with desired fixings.