Ingredients
1 Cornish game hen (1 3/4 pounds), trimmed of excess fat
Kosher salt and freshly ground pepper
3 medium carrots, peeled and quartered lengthwise
1/2 small celery root, peeled and cut into 1/2-inch matchsticks
2 tablespoons extra-virgin olive oil
1 teaspoon Dijon mustard, plus more for serving
2 tablespoons fresh lemon juice
2 teaspoons capers in brine, drained and coarsely chopped
2 tablespoons chopped fresh tarragon leaves
Preparation
Preheat oven to 425 degrees with racks in top and bottom. Place hen, breast-side down, on a work surface. Using kitchen shears, cut along both sides of backbone to remove. Flip over; split lengthwise with a heavy knife. Pat dry; season with salt and pepper. On a rimmed baking sheet, toss vegetables with 1 tablespoon oil; season with salt and pepper. Transfer sheet to bottom rack of oven.
In an ovenproof skillet, heat remaining oil over medium-high. Add hen, skin-side down; cook until browned, about 3 minutes. Flip; transfer skillet to top rack of oven. Roast, stirring vegetables once, until golden, and a thermometer inserted into thickest part of hen thigh reads 165 degrees, 18 to 20 minutes for hen, and 25 to 28 minutes for vegetables. Transfer hen and vegetables to a platter. Return skillet to medium heat; whisk in mustard, lemon juice, 1 tablespoon water, and capers. Cook until reduced slightly, about 1 minute. Stir in tarragon; spoon over vegetables. Serve, with more mustard.
