In a large bowl, add the beef, fish sauce, and Worcestershire sauce. Using a fork or your hands, mix gently until just combined, do not over mix or you get a tougher burger.

Divide the mixture into 4 sections and using your hands, form into patties and place them on a baking sheet lined with foil. Do not pack the beef too tightly or compact it as this will result in tough burgers. Using your thumb, form a slight indent into the center of each patty. Cover the tray with plastic and refrigerate for at least half an hour, or up to a day.

When ready to cook, remove the burgers from the fridge. Heat a heavy bottomed skillet over high heat until quite hot, cast iron would be perfect. Add the butter or oil. Season the burgers with a sprinkle of salt (this helps form a nice crust) and place gently in the pan. They should sizzle violently if the pan is hot enough.

Cook, flipping every couple of minutes until desired doneness. 10-12 minutes for well done, less if you prefer medium/rare. Do not overcook or the burgers will dry out. Also, do not press down on the burgers while cooking or poke them or pierce them in any way, just let them cook in peace until nicely browned all over.

If using cheese, add on the top a minute before you remove from the pan.

Remove the patties from the pan to a plate to rest just for a couple of minutes, meanwhile return the pan to the heat and place your sliced buns in (cut side down) to toast for a bit and soak up all the lovely juices left in the pan from the burgers.

Assemble the burgers with toppings of your choice. Enjoy.