|Sliced fresh mushrooms||1 Pound|
|Margarine||9 Tablespoon, melted and divided (1/2 Cup Plus 1 Tablespoon)|
|Dry sherry||1⁄2 Cup (8 tbs)|
|Salt||1 1⁄2 Teaspoon, divided|
|Ground white pepper||1⁄2 Teaspoon, divided|
|Skinless boneless chicken breast halves||24 Ounce (6 Pieces, 4 Ounce Each)|
|Chopped onion||1⁄2 Cup (8 tbs)|
|Minced garlic||1⁄2 Teaspoon|
|All purpose flour||6 Tablespoon (1/4 Cup Plus 2 Tablespoons)|
|Half and half||2 1⁄2 Cup (40 tbs)|
|Canned ready to serve chicken broth||1 1⁄2 Cup (24 tbs)|
|Shredded fontina cheese||1 Cup (16 tbs)|
|Freshly grated parmesan cheese||3⁄4 Cup (12 tbs), divided|
|Linguine pasta||16 Ounce, uncooked (1 Package)|
|Fine dry breadcrumbs||1⁄4 Cup (4 tbs)|
Saute mushrooms in 2 tablespoons margarine in a skillet 5 minutes.
Add sherry; cook 2 minutes or until reduced to 1/4 cup.
Add 1/2 teaspoon salt and 1/8 teaspoon pepper.
Place chicken in a saucepan; add water to cover.
Bring to a boil; cover, reduce heat, and simmer 20 minutes.
Drain; let cool, and shred.
Cook onion in 1/4 cup plus 2 tablespoons margarine in a saucepan over low heat 15 minutes.
Add garlic; cook 1 minute.
Add flour, stirring until smooth.
Cook 1 minute, stirring constantly.
Add half-and-half and chicken broth; cook over medium heat, stirring constantly, until thickened.
Remove from heat; add fontina cheese, 1/2 cup Parmesan cheese, 1/2 teaspoon salt, and 1/8 teaspoon pepper.
Stir until cheeses melt.
Cook linguine according to package directions; drain.
Combine mushroom mixture, chicken, cheese mixture, 1/2 teaspoon salt, and 1/4 teaspoon pepper.
Stir in linguine.
Spoon into a greased 13- x 9- x 2-inch dish.
Combine breadcrumbs and remaining 1/4 cup Parmesan cheese and 1 tablespoon margarine; sprinkle over chicken.
Bake, uncovered, at 350° for 20 minutes.