1. Bring a large pot of water to a boil. Cook noodles until just tender, 6 to 8 minutes or according to package directions, Drain and rinse.
2. Position rack in upper third of oven and preheat broiler.
3. Meanwhile, heat oil in a large ovenproof skillet over medium-high heat. Add onion, mushrooms and salt
and cook, stirring often, until the onion is softened but not browned, about 5 minutes. Add wine
and cook until evaporated, 4 to 5 minutes. Sprinkle flour over the vegetables; stir to coat. Add milk and pepper and bring to a simmer, stirring constantly. Stir in tuna, peas and 1/2 cup Parmesan cheese until evenly incorporated. Then, stir in the noodles (the pan will be very full). Remove from the heat.
4. Sprinkle the casserole with breadcrumbs and the remaining 1/2 cup Parmesan. Broil until bubbly and lightly browned on top, 3 to 4 minutes.
Make Ahead Tip:
Prepare through step 3, spoon into an 8-inch-square glass baking dish, cover with foil and refrigerate for up to 1 day. Sprinkle with breadcrumbs and cheese (step 4) and bake, covered @350
degrees for 50 minutes. Uncover and cook until browned and bubbly, about 15 minutes more.