Chill the trimmed beef in the freezer for 15–20 minutes until very cold but not frozen solid. Using a sharp knife, cut the beef into 1/4-inch strips and then into fine dice. Aim for an even small dice for good texture.

Mix aromatics and seasoning

In a bowl combine the minced shallot, diced cornichons, chopped capers, chopped parsley, Dijon mustard, Worcestershire sauce, lemon juice, sea salt and black pepper. Stir to combine.

Combine beef and dressing

Add the diced beef to the bowl and gently fold in the extra-virgin olive oil until evenly coated. Taste and adjust seasoning — add a touch more salt or lemon if needed. Keep chilled until plating. If using egg yolks, reserve them for plating (see plating step).

Celeriac Purée

Place celeriac cubes in a saucepan and cover with cold water. Add a pinch of salt. Bring to a simmer and cook until very tender, about 12–15 minutes. Drain well.

While still hot, transfer celeriac to a blender or use an immersion blender. Add the butter and about half the milk/cream. Puree until smooth, adding remaining milk a little at a time to reach a silky, pipeable consistency. Season with salt and white pepper. Keep warm or refrigerate briefly and reheat gently before plating.

Pickled Radish

Combine rice vinegar, water, sugar and salt in a small saucepan and heat just until sugar dissolves. Remove from heat and cool slightly.

Place the thin radish slices and optional ginger in a jar or bowl and pour the warm pickling liquid over them. Let sit at room temperature at least 20 minutes, or refrigerate for up to 24 hours. Drain before using.

Garnish & Assembly

Plate the dish: spoon or pipe a smear of warm celeriac purée onto each plate as a base (about 2–3 tablespoons). Form the beef tartare into a neat mound using a ring mold (about 120–150 g tartare per serving) and place it on the purée.

Arrange a few pickled radish slices around or atop the tartare for acidity and crunch.

Place a small quenelle or spoonful (about 1/2 tsp) of caviar on top of the tartare or beside it. If serving with egg yolk, make a small shallow well in the top of the tartare and add one yolk per two servings or as preferred.

Finish with microgreens or chives, a light drizzle of olive oil, and a grind of black pepper. Serve immediately with toasted baguette slices or crackers.