Mix salt and sugar and put half of the mix in a plate. Place the yolks in the plate and cover with the other half of the mix. Set aside for 40 about minutes. After this time, gently bathe yolks in water for 5 minutes to clean and set aside to drain on a paper towel lightly brushed with olive oil.
Chop acorn-fed Ibérico ham in small cubes and set aside. Chop gherkins, fresh chives and capers, and mix with vinegar, mustard and some olive oil in a bowl. Add Ibérico ham cubes, and mix with some Ibérico pork lard. Season with salt and black pepper. Mix together all of the ingredients until the mix starts to bind together.
To serve, divide mixture into 2 equal portions, and shape each into an oval disk on a serving plate.
Top with a cured egg yolk and accompany with a slice of sourdough bread and rocket. Season and serve immediately.