In a skillet, heat the olive oil over medium heat. Add the chopped onions and sauté until translucent, about 4-5 minutes. Add the minced garlic and stir for an additional minute until fragrant. Allow to cool slightly.
In a large mixing bowl, combine the ground turkey, sautéed onion and garlic mixture, chopped spinach, crumbled feta, breadcrumbs, dried oregano, black pepper, and salt. Use your hands to mix everything together until well combined, being careful not to overmix.
Divide the mixture into equal portions and shape them into burger patties. You'll get about 4-5 patties depending on desired thickness.
Preheat a grill or skillet over medium-high heat. Cook the turkey burgers for about 5-7 minutes on each side or until the internal temperature reaches 165°F (74°C) and they are golden brown.
If using burger buns, you can lightly toast them on the grill or in a toaster while the patties are cooking.
Assemble the burgers on the toasted buns, and add your favorite toppings such as lettuce, tomato slices, cucumber, and a dollop of tzatziki sauce for extra flavor.
Notes
Serve with whole wheat buns and your favorite toppings.