Preheat the oven to 400°F;
Make the flax egg by blending 1 tablespoon of flaxseed and mixing with 3 tablespoons of water, let it sit;
Pull the lion's mane mushroom apart by hands into shreds, heat a large drizzle of oil in a nonstick pan, pan sear the mushrooms, undisturbed for 3-4 minutes till golden, then flip and cook for another 2-3 minutes;
Add the old bay seasoning, garlic powder, onion powder, and 1 tablespoon coconut amino to the mushrooms, stir to mix well, and cook till the moisture is let out, set aside;
In the same pan, saute the onions, carrots, and celeries with the other tablespoon coconut amino till soft;
In a mixing bowl, mash the chickpeas with a potato masher, leaving some texture;
Add the mushrooms, veggies, flax egg, ground oats, salt and pepper to the bowl and mix together;
Shape the mixture into patties and arrange on a lined baking sheet, bake for 15 minutes, flip halfway;
Meanwhile, prepare the tartar sauce, blend together the silken tofu, lemon juice, milk or water, and mustard till very smooth, then mix in the chopped dill and capper, store any extra sauce in the fridge for up to a week;
Serve the crabcakes with the sauce, enjoy!