Pasta Tetrazzini (American Italian)

This pasta was created in the early 1900's by a great American chef for an Italian opera star named Luisa Tetrazzini. This is a nearly forgotten recipe in restaurants of today's age. "Greasy Spoon" Diners do serve a very bastardized version of this recipe, but it is worth avoiding! Remember, this pasta was named for a famous opera diva. So it should look like it was made for an Italian opera diva, with Italian cooking style.
Pasta:
1 lb long pasta (spaghetti, fettucine, linguine, etc.)
4 Tbsp. sea salt
sea salt
pepper, freshly cracked
6 Tbsp. butter
1 lb white mushrooms, trimmed and sliced ¼" thick
½ cup flour, unbleached
3 cups milk or cream
1 (14½) oz can chicken broth
½ cup almonds, roasted and chopped or slivered
¾ cup dry white wine
3 cups Parmesan cheese, grated
½ tsp. dried thyme leaves
4 cups chicken or turkey, cooked, skinned and diced or shredded
1 (10 oz) pkg frozen peas, thawed and drained
Preheat oven to 400°F.
Make Pasta: Bring a large pot of salted water to a boil.
Cook Mushrooms: In a large saucepan, melt 2 Tbsp. butter over high heat. Add mushrooms, and season with salt and pepper. Cook, tossing frequently, until tender and browned, 8-10 minutes. Transfer to a bowl, and set aside.
Make sauce: In same saucepan, melt remaining 4 Tbsp. butter over medium heat. Add flour, cook, whisking, about 1 minute. Whisking constantly, gradually add milk, broth, almonds, and wine. Bring to a boil, reduce to a simmer, and add 2 cups Parmesan and thyme. Season with salt and pepper.
Cook pasta 2 minutes less than pkg instructions for al dente, drain and return to pot. Add sauce, chicken, peas, and mushrooms. Toss well to combine.
Divide between two shallow 2-quart baking dishes, sprinkle with remaining Parmesan. Freeze (see below) or bake until browned, about 30 minutes. Let stand 10 minutes before serving.
Makes 8 servings.