Clean the leek, cut into rings, wash thoroughly and drain. Roughly dice the ham. Heat the oil in a pot and sauté the leek in it over medium heat for about 3 minutes. Add diced ham and steam for another 2 minutes. Remove the pot from the heat and let the mixture cool down a little. Put aside about 2-3 tablespoons of the mixture
Grate the pecorino finely and fold into the leek mixture. Season to taste with salt, pepper and nutmeg. Remove the pasta dough from the packet and unroll it on the baking paper. Spread the mixture evenly along the length of the pasta. Sprinkle with 4 tablespoons of cream. Roll up the dough from a narrow side and put it into an ovenproof dish. Mix the remaining cream and milk. Season with salt and pepper and pour over the pasta roll. Cook in the preheated oven (electric range: 175 °C/ convection oven: 150 °C/ gas: level 2) on the middle shelf for 40-45 minutes. Heat the butter in a pot. Spread the pasta roll with the butter after half the cooking time
Remove the pasta roll from the oven and garnish with the remaining leek mixture