Trim the beef fillet and wrap it carefully in cling film. place the beef fillet in the freezer for two hours (no longer!)
Sour Cream Seasoning (optional): Dry the bunch of chives in a dehydrator overnight for 10 hours at in an oven 60 degrees. When completely dry, blitz in a blender or spice grinder blitz to a fine powder, then mix with the milk powder, onion powder, garlic powder, sugar, MSG, black pepper and citric acid.
Shoestring fries: get the heating oil in a deep pan. Peel the potatoes and slice them finely on a mandolin. Wash the slices in plenty of cold water. Drain in a colander then spread out on a clean tea towel to dry (this will prevent too much spattering from the oil when they are fried). Finely julienne the potato slices.
Prepare a tray lined with kitchen paper and get a slotted spoon.
When the oil is at 170 degree c and add a handful of julienned potato. You will need to do this in a few batches to avoid over crowding the pan and getting them stuck together.
When lightly golden and crispy, remove them from the oil with the slotted spoon and drain on the prepared tray whilst you fry the rest of the chips. Cool and sprinkle liberally with the sour cream seasoning.
Crispy Chilli Oil (optional): very finely slice the shallots and garlic. Put in a pan with the rapeseed oil and fry until golden and crispy. Pass off the oil through a sieve into another pan keeping the garlic and shallots aside.
Place the sliced chillies into a heatproof bowl with the star anise and MSG. Reheat the reserved oil and pour in onto the sliced chilli mix and stir. Add back in the crispy shallots and garlic and set aside.
Tartare Dressing: finely dice the shallot and cornichons, adding them to bowl with the whole grain mustard, the Worcestershire sauce, the olive oil and a dash of sriracha.
Slice the frozen beef fillet into 1/2 cm cubes and toss in a bowl with 3-4 tbsp of the tartare dressing.
Spoon a portion of the tartare onto a plate or bowl, top with an egg yolk seasoned with salt, some picked tarragon leaves, the crispy chilli and some on the shoestring fries.
