Mince the meat in a machine or food processor.
Peel and finely dice the shallot and the garlic. Pick the leaves of the thyme, discard the stalks. Pick and finely chop the parsley leaves. Add these along with the olive oil and mustard to either a food processor or pestle and mix quickly together to make a rough paste. Work this mix into your meat until combined, the texture of the meat should change as you work it. Split the mix into 6 even sized balls around 40/50 grams each in weight and squeeze them gently from hand to hand a few times. Working the meat will help it bind together so don't be shy!
Flatten to a disk rather than ball and chill till needed.
Cut the lemon in half and squeeze the juice into a bowl with the egg yolks and mustard and whisk together. Whilst continuously whisking, slowly add the sunflower oil until it is a thick and smooth mayonnaise. Season with the salt and pepper to taste.
Make sure the cheese is at room temperature, cut into 6 slices
Place the sunflower oil in a deep saucepan and bring to 160'C. Place a few sheets of kitchen roll on a plate ready to drain the shallot rings.
Peel the shallot, leaving it whole. Slice 1/2 cm rings and separate them. Once then onions have been separated, shake them through the plain flour ensuring they are well coated.
When the oil is at the correct temperature, add a small handfull of the shallot rings with as little excess flour as possible. Fry them for 30 seconds until golden brown and crispy. Remove them from the oil using a slotted spoon and place onto the kitchen roll. Repeat the process until all of the shallot rings are fried.
Season the shallot rings with the salt.
Heat a non stick frying pan or griddle. When the pan is hot, add the burgers and fry for 2 minutes on each side on a high heat. Remove form the heat and allow to rest for 2 minutes.
Warm the buns up on the griddle or dry the pan with kitchen paper and use that.
When the burgers are cooked, place them into the burger buns, top with the truffle mayonnaise and finish with some crispy shallot rings and sliced Reblochon.
«For real indulgence try using Wagu beef, its extra fat makes a tasty burger and stops them drying out.»