In a large mixing bowl, combine the ground chicken, fresh spinach, shredded white cheddar cheese, breadcrumbs, finely chopped onion, minced garlic, Dijon mustard, Worcestershire sauce, salt, and black pepper. Mix gently until evenly combined.

Divide the mixture into four equal portions and shape each into a round patty, about ¾ inch thick, making a slight indentation in the center.

Preheat a skillet over medium heat and add olive oil until it shimmers. Cook the patties for 5-6 minutes on one side until golden brown.

Carefully flip the patties and cook for another 5-6 minutes until fully cooked through (165°F internal temperature).

Transfer the patties to a plate and let them rest for a couple of minutes to allow juices to redistribute.

Assemble the burgers by placing each patty on a bun and adding your desired toppings.