Prep the Cucumber: Grate the peeled cucumber, then place it in a cheesecloth or clean towel. Squeeze out any excess moisture to avoid a watery tzatziki.

Combine Ingredients : In a medium bowl, mix together the grated cucumber, Greek yogurt, lemon juice, olive oil, minced garlic, sea salt, and chopped dill. Stir until well combined.

Chill the Sauce: Cover and refrigerate the tzatziki sauce for at least 10-15 minutes to allow the flavors to meld.

Combine Burger Ingredients: In a large bowl, combine the ground turkey, chopped spinach, crumbled feta, grated sweet onion, whisked egg, minced garlic, dried basil, salt, and pepper.

Form Patties: Divide the mixture into 4 equal portions and shape each portion into a patty, about 3/4-inch thick.

Cook the Burgers : Heat a non-stick skillet or grill pan over medium-high heat. Lightly oil the pan, then cook the turkey patties for about 5 minutes per side, or until they reach an internal temperature of 165°F (75°C) and are golden brown.

Assemble and Serve: Serve the spinach feta burgers with a generous dollop of tzatziki sauce on top. You can enjoy them on a bun, in a lettuce wrap, or with a side salad.