Mince the beef through a hand grinder on a medium setting into an very cold, preferably iced, bowl. Do the same with the pork fat. Mix together and refrigerate.
Peel and finely dice the shallots and garlic, pick the thyme leaves adding this mix to the meat and seasoning with salt and pepper. Add the egg yolk and a splash of water to help bind the mix before mixing well with your hands. Shape into patties weighing approximately 125 grams.
To cook, heat a frying pan until very hot and add a drizzle of sunflower oil. Cook the burgers on both sides until nicely caramelised. Turn occasionally to ensure they cook evenly. Depending on the thickness of the burger this will take no more than 10 minutes to be cooked to medium.
Slice the tomato and the red onion.
Cut the burger bun in half and toast under the grill. Spread BBQ sauce on both sides. Add a few leaves of rocket, a slice of tomato and a slice of red onion and then top with the burger.
«Try different spice and herb combinations to make your own signature burger. Chillies, parsley, smoked paprika, cumin and coriander all work well.»