- 1½ cups lightly packed, fresh, soft whole-grain bread crumbs (from about 3 to 4 large slices) (see notes)
- 1 teaspoon Italian seasoning or all-purpose seasoning
- ½ teaspoon chili powder
- ½ teaspoon garlic powder
- ⅛ teaspoon sea salt
- ½ cup chopped walnuts
- 2 cups chopped mushrooms
- ⅓ cup diced onion
- 1 teaspoon reduced-sodium tamari or ¼ teaspoon sea salt
- Preheat the oven to 375 degrees F. Line a medium baking pan with unbleached parchment paper.
- Put the bread crumbs, Italian or all-purpose seasoning, chili powder, garlic powder, and salt in a large bowl.
- Put the walnuts in a blender and process in pulses until they resemble coarsely ground flour. Add the walnuts to the bread crumbs and stir gently to incorporate. Put the mushrooms, onion, and tamari in a blender and process to a chunky purée. Add the mushroom mixture to the walnut–bread crumb mixture and stir to incorporate.
- Place a 3-inch cookie cutter ring on the parchment. Pack one-quarter of the mushroom– bread crumb mixture into the ring and press it firmly and evenly into the ring to form a “burger.” Gently remove the ring. Repeat with the remaining mushroom–bread crumb mixture. Flatten each burger slightly with the back of a flat spatula.
- Bake for 18 minutes. Flip each burger and bake for an additional 15 to 25 minutes, or until the burgers are slightly crisp and golden.
- Serve on sandwich buns, topped with lettuce, tomato, sweet onion, mustard, and catsup
Tips/TechniquesGluten-free option: To make gluten-free bread crumbs, use your favorite gluten-free bread in place of the wholegrain bread. To make fresh bread crumbs, put 3 to 4 large slices of wholegrain bread in a blender and process into coarse crumbs.