Pour stock into a 10-inch skillet and add dill seeds and bay leaves. Cover and bring to a simmer.
Add cauliflwer, cover, and continue to simmer until cauliflower is tender, about 7-8 minutes.
Uncover the skillet and place it in the refrigerator. Let cauliflower chill in its stock for about 30 minutes.
Drain cauliflower reserving stock, and place it in a serving dish. Strain stock and combine 1/4 cup of it with mustard.
Drizzle sauce over cauliflower, sprinkle with minced dill, and serve.
Servings: 4