Potato chips:

1. Slice the potatoes paper-thin using a mandoline. Submerge in cold water and refrigerate overnight.
2. Drain the potatoes and place in a bowl. Bring 1 liter of water to a boil with the 15 g of salt. Pour the boiling water over the potatoes and let soak until they turn brighter in color and are almost tender, 3–5 minutes. Drain and dry thoroughly on paper towels.
3. Heat the neutral oil in a deep pan to 130–140°C (265–285°F). Fry the potato slices in batches until no more bubbles appear, indicating the moisture is gone. Remove and drain on paper towels. Let cool. (They will crisp further as they cool.)

Egg cream:

1. Chop the carrots into large pieces and boil for 20–25 minutes until very tender. Drain, wrap in a clean kitchen towel, and squeeze out as much moisture as possible. Weigh out 40 g of the mashed carrot.
2. Boil the eggs for 8 minutes. Rinse under cold water, peel, and separate the yolks from the whites. Reserve the yolks.
3. In a blender, combine the egg yolks, mashed carrot, caper brine, apple cider vinegar, reduced chicken stock, and a pinch of salt. Blend until smooth.
4. With the blender running, slowly drizzle in the grapeseed oil and then the peanut oil until the cream is thick and emulsified. Season with lemon juice and sea salt to taste.
5. Transfer the egg cream to a piping bag and refrigerate until needed.

Beef tartare:

1. Mince the beef as finely as possible: slice into thin strips, then turn and cut into thin strips again, then chop into tiny dice. Alternatively, grind briefly in a cold meat grinder.
2. Mix the minced beef with the whole grain mustard and olive oil. Season generously with sea salt and freshly ground pepper. Keep refrigerated until assembly, up to 30 minutes.

Final arrangement:

1. Toast and butter the rye bread slices. Divide the beef tartare evenly over the 4 slices.
2. Pipe or spoon the egg cream over each tartare. Top with capers, cornichons, and shallot rings.
3. Stick potato chips upright into the tartare and scatter with fresh tarragon leaves. Serve immediately.