Bake the puff pastry on a baking sheet until all puffy and delicious, about 10 minutes. Set aside and increase oven temperature to 400 degrees F.
Drain the crawfish tails and squeeze excess liquid out. (Wet tails can effect the thickness of the finished sauce.)
In a pot of salty water, cook the potatoes until they are softened but have a little crunch still left in them, then drain and set aside.
Add the turnips to a pot of BOILING salty water. Cook until softened, then drain and run under cold water. Set aside.
In a medium saucepan (big enough to hold all the ingredients), melt the butter. When the butter is melted and bubbling, add the flour and blend in with a whisk. Keep whisking on medium heat for 5 minutes (do not brown, you are just cooking some of the floury flavor out).
Add the stock and cream, then increase heat to medium-high. DO NOT STOP STIRRING. As it heats up the mixture will get thicker. Add the Worcestershire, porcini powder, hot sauce, and salt, pepper and Creole/Cajun seasoning to taste. Cook until the bechamel mixture is thickened and bubbly, then add the drained crawfish and mix in. Cook, stirring, until the mixture returns to a boil. (If the mixture needs more thickening you can do it with a mixture of flour and butter, a tablespoon at a time, waiting for it to return to a boil each time. This is as thick as it's gonna get.)
Add the peas and carrots, pearl onions, potatoes and turnips. Stir gently, so as not to break up the potatoes and turnips.
Spoon the mixture in vessel of your choice and top with the cooked puff pastry. Put the whole thing back into the oven.
Have a beverage. Cook until and bubbly and the puff pastry is starting to brown. Garnish with fresh parsley and/or dill. Serve with lemon wedges and hot pepper infused vinegar.
Domestic crawfish meat is a little sweeter and milder than imported, but it's not always available, and imported stuff will work just fine. Any seafood market and most Asian food market will have them. Domestic is available for shipping online.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of The Front Porch, San Francisco, CA