Clean and wash the leek and remove the hard greens. Pre-cook the sticks in salted water for about 10 minutes.
Brush the cooked ham slices with mustard, wrap each leek with a slice of cooked ham and place in an ovenproof dish.
Make a roux from margarine, flour and broth. Dissolve the processed cheese in it (if necessary, dilute the sauce with water) and season with paprika powder and salt.
Pour the sauce over the leek. Sprinkle everything with grated cheese, paprika powder and breadcrumbs and bake in a preheated oven at 200 ° C for about 15-20 minutes.