Melt the butter in a saucepan, then sprinkle with flour and stir vigorously (stoving). Add the cream and also the garlic, which is finely chopped beforehand.
Fry the bacon in a pan and also add it to the saucepan. Now add the peeled and cut asparagus and season carefully with salt and pepper. It is better to season a little more often so that the asparagus does not lose its own taste.
Bring the whole thing to a boil briefly and then switch back to the lowest level. Finally add the parmesan and simmer on the lowest level for twenty minutes.