Heston: "The secret to a really tender burger is all in the way the meat is ground or more specifically, how it is treated after grinding. By ensuring the individual strands of meat face in the same direction as outlined below, you will guarantee succulent burgers every time. How you garnish your burger is up to you but for me, it has to be with melted cheese, mustard and dill pickles.If you cannot get brioche buns, go for really soft rolls, otherwise the filling will squish out. If you can’t get sweet onions, soak the onions in water for 10 minutes or quickly blanch them in boiling water for 30 seconds."