Poached Fish with Russian Sauce

• 2 tablespoons extra virgin olive oil
• 1/2 pound fresh button mushrooms, cleaned and sliced
• 1 small onion, chopped
• 1 pound tomatoes, cored and chopped (canned are fine), with their juices
• 1/4 cup good-quality black olives, pitted
• 1/2 cup diced sour pickles (cornichons are good; do not use sweet pickles)
• 1 tablespoon drained capers
• 1 cup fish stock, preferably homemade (page 161), or water
• Salt and black pepper to taste
• 1 1/2 to 2 pounds fillets of carp, sturgeon, sea bass, red snapper, or other firm fish, skin removed
• 2 tablespoons cornstarch
• 1/4 cup chopped fresh parsley leaves for garnish

1. Put the oil in a deep skillet and turn the heat to medium-high.
2. A minute later, add the mushrooms and onion and cook, stirring occasionally, until softened, about 5 minutes.
3. Add the tomatoes and cook until they break down and release their juices, about 10 minutes.
4. Stir in the olives, pickles, capers, stock, and salt and pepper and bring to a steady simmer.
5. Sprinkle the fish with salt and pepper, then gently slide the fillets into the stock and cook just until a thin-bladed knife passes through with little resistance, less than 10 minutes.
6. Transfer the fish to a warmed serving dish.
7. Bring the sauce to a boil and reduce slightly.
8. If you want a thickened sauce, as is traditional, mix the cornstarch with 2 tablespoons cold water and stir into the sauce.
9. Lower the heat, then simmer until the sauce thickens; taste and adjust the seasoning.
10. Spoon the sauce over the fish, garnish with parsley, and serve.

extra virgin olive oil, button mushrooms, onion, tomatoes, black olives, sour pickles, capers, fish stock, salt, red snapper, cornstarch, parsley

Taken from www.epicurious.com/recipes/food/views/poached-fish-with-russian-sauce-386198 (may not work)