For the noodles, boil 3-4 l salted water (1 teaspoon salt per litre). Clean, wash and cut the leek into rings. Crumble bread roughly.
Heat butter in a frying pan. Roast breadcrumbs and diced ham in it while turning, remove. Wipe the pan with kitchen paper, then heat the oil in the pan. Sauté the leek for about 2 minutes.
Add the pasta to the boiling salted water and cook according to the instructions on the packet. Sprinkle leek with flour, sweat it and while stirring, deglaze with cream and 1⁄4 l water. Bring to the boil and simmer for about 5 minutes.
Stir in horseradish. Season sauce with salt and pepper.
Drain the pasta and mix with the sauce. Serve and sprinkle with the ham and breadcrumbs mix.