Chicken Tetrazzini

Directions

1. 1
   Bring chicken bones, broth, carrot, onion, celery, garlic, peppercorns, bay leaf, and cloves to a boil in a 3- to 4-quart heavy saucepan, then simmer, partially covered, skimming froth, 30 minutes.
2. 2
   Pour stock through a large sieve into a bowl, discarding solids, and return to saucepan.
3. 3
   Measure stock: If more than 2 cups, boil until reduced.
4. 4
   Keep warm, covered.
5. 5
   Put oven rack in middle position and preheat oven to 350F.
6. 6
   Butter a shallow 3-quart glass or ceramic baking dish.
7. 7
   Heat 3 tablespoons butter in a large heavy skillet over moderately high heat until foam subsides, then saute mushrooms with 1/4 teaspoon salt and 1/8 teaspoon pepper, stirring, until liquid mushrooms give off is evaporated and mushrooms begin to turn golden, about 8 minutes.
8. 8
   Melt remaining 3 tablespoons butter in a 2- to 3-quart heavy saucepan over low heat, then add flour and cook roux, whisking, 3 minutes.
9. 9
   Add warm stock in a fast stream, whisking constantly, and bring to a boil.
10. 10
    Reduce heat and simmer, whisking occasionally, 5 minutes.
11. 11
    Add cream, Sherry, remaining 1/4 teaspoon salt, and remaining 1/8 teaspoon pepper and simmer over low heat, whisking occasionally, 10 minutes.
12. 12
    Stir in truffle butter (if using).
13. 13
    Cook spaghetti in a large pot of >boiling salted water until al dente, then drain well.
14. 14
    Toss together spaghetti, mushrooms, and half of sauce in a large bowl, then transfer to baking dish.
15. 15
    Stir together chicken meat and remaining sauce in same large bowl.
16. 16
    Make a depression in spaghetti, then spoon chicken into it and sprinkle dish with cheese.
17. 17
    Bake until sauce is bubbling and top is lightly browned, about 30 minutes.
18. 18
    Serve immediately.
19. 19
    *Available at some specialty foods shops and D'Artagnan (800-327-8246).