Season burger with sea salt and oregano on both sides. I made my beef patties from ground beef because I like mine a bit thicker. If using ground beef make a 1/4 cup sized ball and then flatten into a patty, then season. But you can use premade patties, that works too.
Heat pan to medium high heat, add olive oil or oil or choice. Make sure it's hot, then add the burger patty, press down with a spatula so all sides are touching the pan. Or grill them on the grill, both ways will be great. Cook for about 4-6 minutes a side. Whatever is your desired cook on beef. Flip and cook the same amount of time on the other side. Once done, on bed of arugula.
Finely dice cucumber and tomato into small cubes. Slice olives into thirds. Mix together with olive oil and sea salt. Taste for seasoning. Top the burger with salad.
Crumble feta cheese on top of salad and burger, add desired amount of LENASKITCHEN PICKLED ONIONS and a sprinkle of fresh thyme. Enjoy!