Sauce Froide de Moutarde pour Asperges et Artichauts de Mme Vignon

I had arrived to talk to M. Vignon about his chestnut bread. As we walked into the bakery to check some details on the flour bags we met Mme Vignon in her tiny, neat cuisine de coin tucked in behind the shop. She was scraping some fat white sticks of asparagus to serve for lunch. We discussed sauces for asparagus and she insisted on making her own mustard sauce straight away for me to taste. Once the asparagus is over, I find it goes well with globe