SAUCE
Zest of 1 small lemon
1 garlic clove, finely grated
¼ cup plain whole-milk Greek yogurt
¼ cup tahini
3 Tbsp. fresh lemon juice
2 Tbsp. finely chopped mint
½ tsp. sugar
Kosher salt, freshly ground pepper
BURGERS AND ASSEMBLY
1 Tbsp. coriander seeds
2 tsp. cumin seeds
4 Tbsp. (or more) extra-virgin olive oil, divided
1 small white or yellow onion, finely chopped
2 garlic cloves, finely grated
½ tsp. ground cinnamon
1 large egg
1 cup finely chopped cilantro
½ cup panko
1 tsp. Diamond Crystal or ½ tsp. Morton kosher salt, plus more
Freshly ground pepper
1 lb. ground turkey
4 soft sesame seed buns, split
Torn romaine lettuce, thinly sliced red onion, mint leaves, and hot sauce (for serving)
SAUCE
Step 1
Stir zest of 1 small lemon, 1 garlic clove, finely grated, ¼ cup plain whole-milk Greek yogurt, ¼ cup tahini, 3 Tbsp. fresh lemon juice, 2 Tbsp. finely chopped mint, ½ tsp. sugar, and 1 Tbsp. water in a small bowl until smooth. Season generously with kosher salt and freshly ground pepper. Chill until ready to serve.
Do ahead: Yogurt sauce can be made 1 day ahead. Cover and keep chilled.
BURGERS AND ASSEMBLY
Step 2
Coarsely crush 1 Tbsp. coriander seeds and 2 tsp. cumin seeds with mortar and pestle or very coarsely grind in spice mill.
Step 3
Heat 2 Tbsp. extra-virgin olive oil in a large skillet, preferably cast iron, over medium. Cook 1 small white or yellow onion, finely chopped, stirring occasionally, until softened and translucent, 5–7 minutes. Add spice mixture, 2 garlic cloves, finely grated, and ½ tsp. ground cinnamon; cook, stirring often, until spices are fragrant, about 1 minute. Scrape onion mixture into a large bowl; wipe out skillet and reserve.
Step 4
Add 1 large egg, 1 cup finely chopped cilantro, ½ cup panko, and 1 tsp. Diamond Crystal or ½ tsp. Morton kosher salt to onion mixture, season with freshly ground pepper, and mix to combine. Add 1 lb. ground turkey and gently mix with your hands until just incorporated (do not overmix). Using damp hands, form into four 4"-diameter patties.
Step 5
Heat 2 Tbsp. extra-virgin olive oil in reserved skillet over medium-high. Season patties generously on both sides with salt and pepper. Working in 2 batches and adding more oil between batches if needed, cook patties, undisturbed, until deeply browned underneath, about 5 minutes. Flip and cook, undisturbed, until deeply browned on second side and cooked through (an instant-read thermometer inserted into center should register 165°), about 4 minutes. Transfer to a wire rack. Wipe out skillet.
Step 6
Working in batches, toast 4 soft sesame seed buns, split, cut side down, in same skillet until golden brown and crisp around edges, about 3 minutes. Transfer to rack.
Step 7
Arrange burgers, buns, torn romaine lettuce, thinly sliced red onion, and mint leaves on plates with yogurt sauce and hot sauce alongside and let everyone build burgers as desired.