Heat coconut oil in pan at medium-high heat. Add onion, garlic and mushrooms and sauté 7-10 minuets (until onions are translucent).
Prepare flax "egg" by combining flax seeds with 3 tbs warm water. Let sit for at least 10 minutes before using.
Combine garlic/onion mixture in a large bowl with beans and lentils. Using an immersion blender, blend until 75% smooth. I like to leave a little texture. Stir in remaining ingredients (including flax egg).
Wet hands and form mixture into patties ½"- 1" thick.
Place patties on baking sheet. Bake for 35 minutes, flipping halfway. Enjoy right away, store in refrigerator for 4 days or freeze for longer storage.
Recipe by The Colorful Kitchen at https://thecolorfulkitchen.com/2014/08/15/vegan-mushroom-lentil-burger/