Bring a large pot of water to a boil. Cool noodles until just tender, about 6-8 minutes or according to package directions. Drain and rinse.

Position rack in upper third of oven and preheat broiler.

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, about 4-5 minutes. Sprinkle flour over vegetables; stir to coat. Add milk and pepper and bring to simmer, stirring occasionally. Stir in tuna, peas and 1/2 cup Parmesan until evenly incorporated. Then, stir in the noodles (the pan will be very full). Remove from heat.

Sprinkle the casserole with breadcrumbs and the remaining 1/2 cup Parmesan. Broil until bubbly and lightly browned on top, about 3-4 minutes.