Melt 2 tablespoons of butter in the pan and toss the vegetables prepared as usual. Add the salts and the sugar. Top up with the broth and simmer until soft.
Make a sweat with the remaining butter and flour and fill up with the vegetable stock. Simmer for a few minutes over moderate heat. Add the vegetables, season to taste and sprinkle with freshly chopped parsley.
If desired, a little cream or milk can be added to refine.
For the more modern variant, the vegetables are steamed as indicated, then at the end a few flakes of butter are spread over them and some flour is stirred in via a sieve. Stir everything well.
It will be creamy, but not as high in calories as it used to be!