Dr. Kitchiner was known for always traveling with a “portable flavor stash.” It consisted of twenty-eight bottles of his favorite ingredients, such as celery extract, pickles, and, of course, “the” sauce.
Melt the butter in a frying pan. Then mix in the flour and add the beef broth. Stir over low heat until a uniformly thick sauce is formed.
Then add wine vinegar, port, mustard and mushroom concentrate. Season with a pinch of salt and a little black pepper and let the mixture make for about 10 min.
Add parsley and walnuts. Bring everything to the boil once more and bring to the table.
If you add the sauce roast beef, you can be sure of the gratitude of the ox spirit. No information can be given about the shelf life – this question has never arisen until now.
However, with small changes in the amounts of vinegar and mustard, noticeable changes in taste can be achieved. A far more tart sauce is obtained by using 1 tbsp. vinegar and 1 tsp. mustard. ~Feel free to experiment.
Mushroom concentrate: take six large young mushrooms, put them in a suitable bowl, sprinkle them with a little salt and grind them after about 3 hours. Then cover the baking dish and let it stand for one night.
The next morning, put the liquid in a frying pan (you keep a little bit more if you cook the mushroom porridge through e