Vegetarian Mushroom Burgers with Avocado & Grilled Onions

Vegetarian Mushroom Burgers with Avocado & Grilled Onions

Mushroom Burgers

  • 2 cups finely chopped shiitake mushrooms
  • 2 large eggs, lightly beaten
  • 1/2 cup EACH dry bread crumbs, shredded jalapeño jack cheese, finely chopped onion
  • 1/4 cup all-purpose flour
  • 1/2 tsp salt
  • 1/4 tsp dried thyme
  • 1/4 tsp pepper
  • 1 Tbsp canola oil
  • Full Circle Bakery buns
  • thinly sliced jalapeño jack cheese
  • Green leaf lettuce
  • avocado, sliced (1/2 avocado/burger)

Caramelized Onions

  • 1 ½ Tbsp oil
  • 1 onion, sliced
  • 1 tsp sugar
  • ¾ tsp kosher salt


  1. Onions: Heat oil in a large skillet over high heat (cast iron is recommended). Add onions and allow them to sizzle for about 5 minutes, stirring occasionally so they don't stick. Season with the sugar and salt, lower heat to medium-low and cook for 25 minutes, stirring every 7-10 minutes, until browned and caramelized.
  2. Patties: In a large bowl, combine the first 9 ingredients. Shape into four 3/4" thick patties.
  3. Remove onions from pan, set aside and reheat skillet to medium-high. Cook patties for roughly 3-5 minutes per side. When patties are almost done, lay remaining sliced cheese over them and allow it to melt. If desired, toast buns with just a brush of oil and assemble burgers topping with sliced avocado, onions, and lettuce.