Spicy Blackened Burgers

1. Place an iron skillet on a grill set over a high fire, and preheat for 15 minutes.
2. Meanwhile, mix the salt with the white pepper, fennel, black pepper, garlic powder, dry mustard and cayenne.
3. Prepare the burgers according to their recipe, up through the step where the patties are formed.
4. Pat a thin film of the spice mixture on the surface of the burgers.
5. Spray the burgers with vegetable spray and cook the burgers in the skillet for 4 minutes per side.
6. Remove from heat.
7. Transfer burgers to buns.
8. Add the water and worcestershire sauce to the pan and stir to loosen bits sticking to pan. Spoon this liquid over burgers.