Makes 8 tartlets
1 (14.1-ounce) package refrigerated pie dough (2 sheets)
1/4 cup sliced white button mushrooms
1 teaspoon olive oil
1/4 teaspoon dried thyme
1/8 teaspoon salt
1/8 teaspoon ground black pepper
2 tablespoons butter
2 tablespoons all-purpose flour
1 cup beef stock
2 tablespoons red wine
1 tablespoon finely chopped cooked bacon
1/4 cup chopped roasted chicken
1/4 cup pearl onions, blanched
Garnish: fresh thyme
• Preheat oven to 450°.
• Using a (4½-x-2½-inch) tartlet pan as a guide, cut 8 shapes from dough. Press dough shapes into 8 tartlet pans. Place tartlet pans on a rimmed baking sheet. Refrigerate for 30 minutes. Prick tartlet dough with a fork to prevent puffing during baking.
• Bake until edges are golden brown, approximately 7 minutes. Let cool completely before removing from pans.
• Reduce oven temperature to 350°.
• In a small bowl, combine mushrooms, olive oil, thyme, salt, and pepper, tossing to coat. Spread in a single layer onto another rimmed baking sheet.
• Bake until mushrooms are tender and release their juices, approximately 20 minutes. Set aside.
• In a small sauté pan, melt butter over medium-high heat. Add flour, whisking constantly. Cook until a smooth paste forms, 1 to 2 minutes, reducing heat if mixture starts to brown. Add beef stock, whisking and cooking over medium-low heat until mixture is smooth and creamy. Add wine and bacon, stirring to incorporate.
• Spread approximately 2 tablespoons gravy into bottom of each tart shell. Top each with 1 tablespoon chicken, 1 tablespoon mushrooms, and 2 to 3 pearl onions. Sprinkle with fresh thyme leaves and a thyme sprig, if desired.
• Serve immediately.
MAKE-AHEAD TIP:Tart shells, baked mushrooms, and beef gravy may be made a day in advance. Store tart shells in an airtight container at room temperature. Refrigerate mushrooms and gravy in separate airtight containers. Reheat gravy over low heat before assembling tartlets, adding more beef stock to thin, if necessary.