Chicken Tetrazzini

I made this for the first time and husband really liked it.  I am not making many modifications to the recipe, but the timing and sequence.  Note that this will take a while to prep (an hour or a bit more?). However, once it's in the oven, it's easy for you to sit with guests and chat.  Oh, and this is a fattening recipe.

Ingredients
3-4 boneless skinless chicken breasts
1 # sliced button mushrooms
1 large onion, finely chopped
7 cloves garlic, minced
2 tbsp fresh thyme
1/4 c white wine
1/3 c all purpose flour
1 qt whole milk
1 c heavy cream
1 c chicken stock
1/2 c frozen peas
1/4 fresh parsley, minced
1 c parmesan, grated
1/4 c bread crumbs, dried
8 tbsp (1 stick) butter
12 oz dried spaghetti or linguini
1/8 tsp ground nutmeg
kosher salt
black pepper
olive oil

Non-standard supplies
None

Instructions

1. Measure out milk and cream and allow it to warm on counter before you start cooking chicken.
2. Trim chicken, sprinkle liberally with salt and pepper and pan fry in 1 tbsp butter & 1 tbsp oil or 4 min on each side.  If not fully cooked, it's ok.  Remove from pan and rest.
3. In same frying pan, add another 1 tbsp butter and oil and saute mushrooms until liquid is almost gone and mushrooms are golden - 7 or 8 min, approx.  Add onion and thyme to mushrooms and cook until just translucent.  Stir in fresh garlic during last 1 minute of cooking careful not to burn garlic.
4. Remove veggie mixture and place in large mixing bowl.
5. In a large pot, begin boiling water for pasta
6. Without wiping out frying pan, add 3 tbsp more of butter to frying pan and melt over medium low heat..  Whisk in flour and continue whisking for 2 min to create roux.
7. Whisk in milk, cream, nutmeg, 1 3/4 tsp salt and 3/4 tsp pepper.  Cover sauce and bring to boil.  Once boiling, uncover and simmer to thicken.
8. Meanwhile, prepare pasta al dente when water is ready.  Drain.
9. Preheat oven to 450
10. Grease 9x13 baking dish
11. While pasta is cooking, shred/cut chicken into bite size pieces and add to mushroom mixture.
12. Run water over peas to remove ice crystals and add to bowl.  Add parsley, too.
13. Pour wine over mixture.
14. Mix breadcrumbs and cheese in a small bowl.
15. Add pasta to bowl.
16. Ladle in sauce and toss to coat mixture.  Once coated, add one more ladle.  It's ok if you don't use all the sauce.
17. Pour mixture into prepared baking dish.  Top with 2-3 more ladles of sauce on top.  Sprinkle crumb/cheese mixture on top.  Dot with remaining butter.
18. Bake for 25 minutes.  Top will be browned, crunch and sauce will be bubbly.