It is a terrific dish to make for a crowd, as it is easily doubled, holds well, and can be prepared ahead of time and baked just before serving. It also reheats decently.
Kay's Chicken Mushroom Tetrazzini
1 package (12 ounces) fettucine noodles, cooked, drained and rinsed
4 chicken breasts, cooked and shredded
1/3 cup unsalted butter
1 onion, diced
2 cloves garlic, minced
1 cup sliced fresh mushrooms (optional)
1/4 cup flour
2 1/2 - 3 cups milk
1/4 cup sherry (cooking sherry is acceptable, but it is very salty, so adjust your seasonings accordingly)
20 ounces sliced provolone cheese; tear or shred 12 ounces
Coat a 9x13 glass dish with cooking spray and place half the fettuccine noodles in the bottom. Sprinkle with half the chicken and set aside.
In large saute pan, melt butter, saute onion, garlic and mushrooms until soft. Add flour; stir well until bubbly. Slowly add milk, sherry and 12 ounces of shredded/torn cheese. Cook over medium-low heat until cheese melts (mixture will be gloppy.) Pour half the sauce over the chicken. Layer the remaining noodles, chicken and sauce. Arrange remaining cheese slices over top.
At this point, it can be refrigerated overnight or baked for immediate serving. Cover with foil and bake at 375 for 20 minutes; uncover and bake an additional ten minutes or until top is golden and bubbly. If baking from refrigerated state, add at least 5-10 minutes to the covered baking time.