Heat butter in your skillet on medium heat. Place the onions and sauté them till glossy and soft. Following this, add the mushrooms and keep cooking until they shed off their water and turn golden. Final addition of garlic, which is allowed to bloom for about 30 seconds.

Pour in the white wine. This time, it is simmering, so scrape the flavorful bits off the pan. Cutting the wine in half cuts the wine and makes the sauce its trademark.

Add the cream and seafood stock. Heat it to a gentle simmer slowly, and then lower the heat and allow it to become thick. It is not a fast and furious sauce, but rather a low-and-slow masterpiece.

Add lemon, Worcestershire, paprika, white pepper, and salt. Taste and adjust. The taste should be strong and in the middle.

In a different small pan, melt 1 tbsp butter and then saute your shrimp or crawfish as fast as possible to warm them. Fold them and add them to the sauce.

Keep simmering until the sauce is smooth, luscious, and even somewhat thick-thick enough to stick to the back of a spoon.

Served over grilled fish, blackened catfish, seared salmon, or even pasta in abundance. Decorate with parsley, in case you want to be fancy.