Place 180 g of butter in a small saucepan and heat it until the butter turns brown and smells of hazelnuts. Leave it to cool to around 50 degrees and carefully pour it into a 1-litre measuring jug, taking care not to include the dark sediment. Weigh out the browned butter – there should be approx. 150 g. Bring approx. 1 litre of water to the boil in a saucepan, carefully add the eggs and boil them for exactly 4 minutes. Cool the eggs in ice-cold water, peel them and place them in a blender together with the caper brine and capers, lemon juice, sugar, salt and pepper. Blend and add the lukewarm browned butter in a thin stream until everything has emulsified to a smooth consistency. Now pour the oil into the mixture in a thin stream until you have a uniform mayonnaise. Transfer it to a jar or a piping bag and refrigerate.
Boil a couple of medium-sized beetroots in water until tender, peel them and weigh out 150 g. Grate both the boiled and pickled beetroots using a coarse grater and dice the apple into small cubes. Whisk together the olive oil, balsamic vinegar and garlic with a little salt and pepper, then toss with the beetroot and apple cubes. Finally, season to taste with salt and pepper.
Arrange the beetroot mixture on plates in a neat circle, then spoon or pipe small dollops of the browned butter emulsion on top. Next, scatter plenty of cress and finely grated horseradish over the top. Finally, sprinkle with crispy buckwheat and serve immediately.
