Wash, clean, peel the vegetables and cut into bite-sized pieces / slices that are not too large. Cut the celery into small cubes. Halve the leek lengthways and cut into half thin rings.
Put everything in a baking dish, season, pour the wine over it and spread the butter in small pieces over it. Mix everything again and place in the oven at 180 degrees for 45 - 60 minutes, depending on the size of the vegetables.
Remove and refine with the cream. Sprinkle some parmesan over the vegetables if you like.
Fried potatoes or mashed potatoes go very well with it.