Heat 3 tbsp of Cuisine oil and add the sliced onions. Note ( Keep over a medium heat.)
Season with salt and allow the onions to become soft, tender and caramelized. For about 15 minutes. Note (This process takes a while be patient and keep stirring for even cooking.)
Grind flaxseed and place into a bowl holding the 6 tbsp of water. Mix well and set aside
Heat pan and sauté vegetables. Set aside allowing to cool.
Grind walnuts and oats until a powdered form.
Process the black beans as desired. Note (It can be processed until a smooth paste or chunky.)
Add the walnut oat mixture and vegetables to the black bean in the processor. Blend well and transfer to a bowl.
Oil hands, scoop out mixture and form into a patty. Note (We used 1 C measurement only because we had big buns. Feel free to use a ½ C or even ¼ for smaller burgers. )
Place patties onto a greased baking tray lined with foil. Bake the patties on each side for 20 minutes. Note (The bigger the patties the more time it will need in the oven. A little softness in the centre is ok but make sure most of the patty is cooked. It should have a crunchy exterior.)
Process the avocado with the garlic and stream the olive oil. Blend until a smooth paste has been formed. Add salt and black pepper to taste.
Assemble the burger and add any other additional toppings you may like.