Adapted from the New German Cookbook, by Jean Anderson and Hedy Wurz. Posted for ZWT6. The author included directions for making your own fish stock. If you have the time to make your own stock, please use it here, if not, use the best fish stock you can purchase. I thought this would also be excellent with dill replacing parsley for the final garnish.
- Combine the stock and milk in a skillet large enough to hold all of the fish in a single layer.
- Bring to a simmer over medium heat.
- Add the fish, salt, and pepper; and cook uncovered for 5 - 7 minutes, or until the fish just flakes when you touch it with a fork.
- Carefully move the fish to a heated platter, cover, and keep warm.
- Bring the poaching liquid to a boil, and reduce to 1 cup (about 10 minutes).
- Reduce heat to medium, add the cream, and cook for 2 more minutes.
- whisk in the mustard, sugar, and sour cream, bring back to a simmer.
- Whisk in the butter, a bit at a time, until fully incorporated.
- Add any juice that has accumulated on the platter, then strain the sauce over the fish.
- Sprinkle with parsley, then serve immediately.