Rinse the kale leaves under cold water.
Cut the vein from each leaf and discard. Roughly chop the rest of the leaves and transfer to a medium sized bowl.
Sprinkle the kale with the sea salt and massage it through all of the chopped kale.
Slice the tomato into wedges cutting out the seeds. Place the tomato into a food processor.
Add the portobello mushroom, cumin, almond butter, garlic, paprika and black pepper.
Pulse on low speed until smooth and well combined.
Add the flour and gently mix again.
Transfer the mixture back into the bowl that the kale was resting in.
Add the breadcrumbs and fold through with a spatula.
Divide the mixture into 4, forming each one into a patty shape with your hands. Be sure to use some extra flour to dust your hands and prevent it getting too sticky. If it does, wash your hands.
Place each burger onto a cookie tray which has been dusted lightly with flour.
Heat the canola oil in a non stick pan over a medium-low heat. Place the burgers into the hot pan and cook on one side for about 3-4 minutes and the burger has formed a nice dark crust.
Turn over the burgers and repeat on the other side.
Place each burger onto the hamburger buns and dress with your choice of toppings.