Remove your steaks from the fridge 10 minutes before cooking. Preheat the grill in two zones: 1 high heat and 1 medium/low heat.
While preheating, make the yogurt. In a small bowl, stir together the yogurt, lemon juice, olive oil, and spices. Lastly, stir in the mint and the cilantro. Leave a little bit for garnishing.
Cut your steak into 1" cubes and toss with sea salt and Za'atar. Add a little oil to make it stick.
Toss your veggies with salt and a little oil.
Thread your veggies and meat onto the skewers. Make sure onion is always touching the meat.
Grill the skewers for 2 minutes on each of the four sides. If it starts to burn, place over the low heat to continue cooking. It will be easy to overcook, so make sure to test the meat with a thermometer or cut a piece of the meat off with a knife.