Using a food processor or blender, pulse beans until crumbly, but not pureed to leave some texture. Place in a large mixing bowl with zucchini, spices, flax and nuts.
Drizzle in water as needed while roughly mixing ingredients with a fork until mixture begins to hold together when mashed. Shape into 6-8 patties using hands.
Warm coconut oil in a pan over medium heat. Place patty in pan and allow to cook for 3-4 minutes before gently flipping with a spatula. Repeat on other side until nicely browned.
Top with sauteed mushrooms, onions, avocado and tomato. Serve on a lettuce wrap or a toasted bun and enjoy!