Finely Chop the onion and the tomato (You can use your multi blender for this.) and add them with all their juices in a big bowl. Grate the potato and also add in the bowl.
Add in the bowl all the other ingredients and mix them all together very well. (at least 5 min).
Carefully roll the mixture into balls, each about the size of a tennis ball. Set in the palm of your hand and gently squeeze down to flatten into patties. Make sure all the burgers are the same thickness so that they will cook evenly. Bake your burgers in a preheated oven at about 180 Grad for 25'-30' until they are cooked through.
Enjoy with a salad or with potatoes and definitely with some Greek yogurt