Cook dry lentils in simmering water until tender. Drain. You will need 2 cups cooked.
Sauté the onion, garlic, and mushrooms in olive oil over medium heat for 5 minutes. Add a little water if it gets too dry. Turn heat down to low, and cook until very tender and cooked through. Set aside.
Blend the walnuts into a coarse flour. Pour that flour into a medium bowl.
Add half of the lentils and the mushroom mixture, salt, spices, and flax mixture. Mix everything until it’s well combined and forms a thick dough using a hand blender. Then, stir in the remaining whole lentils.
Using wet hands, form into 12-15 little cakes.
Put cakes on a baking sheet with a little oil. Bake them in a 375 degree oven for 10-15 minutes or until they form a crust, before flipping. Cook them for 5 more minutes on the other side.
Serve with the garlic sauce.