Difficulty: Medium
Prepare the sauce: Trim the bottoms from the porcini stems, rinse quickly under cold water, and pat dry on paper towels. Place in a saucepan with the veal stock over medium heat. Bring to a boil, remove from heat, and infuse for 30 minutes. Strain through a fine sieve and adjust seasoning to taste.
Prepare the porcini: Separate the caps from the stems, reserving the caps whole. Dice the stems and set aside. For the filling, heat 1 tablespoon olive oil in a large saucepan with half the sliced shallots over medium heat. Cook for 2 minutes without browning. Add the diced porcini stems and cook, stirring, for 2-3 minutes until lightly browned. Stir in the diced Bayonne ham, breadcrumbs, and thyme sprigs. Season with salt and pepper, mix vigorously with a wooden spoon, then remove the thyme and reserve the filling.
Cook the porcini caps: Heat 1 tablespoon olive oil in a sauté pan over high heat. When very hot, add half the caps and cook, shaking the pan, for 2 minutes until lightly browned. Drain, season with salt, and reserve. Repeat with the remaining caps, adding fresh oil.
Make the garlic butter: In a small saucepan, combine the remaining shallots and white wine. Reduce over moderate heat until the wine evaporates completely, then cool. In a bowl, mix the reduced shallots with the chopped garlic, parsley, and softened butter until well combined.
Season the browned caps with salt and pepper. Heat the garlic butter in a large sauté pan over medium heat, add the porcini caps, and cook uncovered for 3 minutes. Transfer to a board and slice each cap into thin strips with a sharp knife.
To serve: Place a portion of filling in the center of each warm plate. Arrange the porcini slices on top and around it. Garnish with diced Serrano ham shavings, toasted hazelnut halves, and parsley leaves. Drizzle with the sauce and serve immediately.
Recipe by Philippe Groult from the book: L'Atelier de Joël Robuchon
