Make the Mushroom Duxelles: Cook 1 lb finely chopped mushrooms, 2 minced garlic cloves, and thyme leaves in a dry pan over medium heat until all moisture evaporates. Stir in 2 tbsp parsley and cool.

Beef Wellington is a fancy dish that takes planning and effort to make well, but it often hits one major snag: sogginess. Here's how to keep the pastry crisp.