Place ground lamb in a large bowl. Add chopped cilantro, chopped mint, cloves of garlic, kosher salt, black pepper, and a generous pinch or two of ground cinnamon. It’s important not to overmix the meat, or the burgers will be tough. Mix until just fully incorporated.
To make slider-sized patties, weigh each. Flatten into uniform rounds, then use your thumb or finger to make a small indentation right on top in the center of each patty. Allow the patties to sit out before cooking.
Combine all sauce ingredients in a large bowl, then whisk to combine. Refrigerate until needed.
Preheat a grill or cast-iron skillet over medium-high heat. Coat with non-stick oil spray or a couple tablespoons of olive oil. Once hot, cook each burger patty. Allow burgers to rest before serving on buns with tzatziki, pickled red onions, arugula, and any additional toppings you might like. Enjoy!