In a large pot, bring water to boil and cook noodles until just tender. About 7-9 minutes.
Drain and rinse noodles.
Position rack in upper 1/3 of oven.
Preheat broiler.
Heat olive oil in ovenproof large skillet over medium-high heat.
Add onions, mushrooms and salt. Cook until onions soften. Do not let onions brown. Stir often. About 5-6 minutes.
Add wine and cook until wine evaporates. About 4-6 minutes.
Sprinkle flour over vegetables and stir to coat.
Add milk and pepper and bring mixture to a simmer.
Stir constantly.
Stir in tuna, peas and 1/2 cup parmesan cheese until evenly incorporated.
Stir in noodles and remove from heat.
In 6 oven-safe oval porcelain ramekins, spoon equal amounts of mixture.
Sprinkle casserole with breadcrumbs and remaining parmesan.
Broil ramekins until bubbly and browned on top. About 3-5 minutes.