In a large bowl, mix together all of the ingredients except for the oil and lemon slices.
Mix the arrowroot starch and sea salt in a shallow bowl.
Heat a large cast-iron skillet or pan over medium-high heat on the stove (You want a smooth bottomed pan for this to make contact with the burgers).
Add the 3 tbsp of cooking oil to the skillet.
Take a handful of the burger mixture, try to pat it into a burger shape (it will be sticky) and then lay down in the arrowroot powder.
Coat both sides lightly, tap off the excess, then flatten a bit more into a burger shape.
Carefully lay the burger down in the pan.
Repeat until there is no more room in the pan (don't overcrowd, you'll have to do this in 2-3 batches and will make 4-8 patties).
Leave to cook on that side for 5-6 minutes, then flip and cook for an additional 4 minutes (if you notice the coating isn't getting browned, turn the heat up slightly).