Preheat oven to 400. Spray a small baking sheet with cooking spray.
Mix together meat and seasonings in a medium bowl. In a separate bowl mix together spinach, cheeses, and seasonings.
Using half the meat make four patties on the baking sheet. Divide the filling between them. Divide the rest of the meat into four pieces. Take each one and press out into a flat round circle in your hands. Put on top of the filling and press down and around it. Press into the bottom meat to seal the burger.
Bake for 20 minutes or until the burgers are 160 when checked with a meat thermometer.
Nutrition: The nutrition facts are for one burger. This recipe makes 4 burgers. There are 1.4 NET carbs per serving.