Prepare the Ingredients: In a large mixing bowl, combine the ground chicken, red peppers, red onion, feta cheese, spinach, and panko crumbs. Add the minced garlic, dried oregano, salt, black pepper, and lemon juice. Mix thoroughly until all ingredients are evenly incorporated.

Shape the Patties: Divide the mixture into 4-6 equal portions and shape each into a patty about ½-inch thick. Make a small indentation in the center of each patty to ensure even cooking.

Cook the Burgers: Heat a grill, grill pan, or skillet over medium heat. Lightly grease the surface with a touch of oil to prevent sticking. Cook the patties for about 5-6 minutes per side, or until they are golden brown and the internal temperature reaches 165°F (74°C).

Serve and Garnish: Place the cooked patties on your favorite bun or lettuce wrap. Garnish with sliced red onions, extra feta, or a dollop of tzatziki sauce, if desired.

Enjoy: Serve immediately with a side of salad, roasted vegetables, or sweet potato fries for a complete meal.