Preheat the oven to 400 degrees
Boil the noodles in salted water, a minute less than the package recommends.
Heat a deep skillet over medium heat, then melt 2 Tbsp butter
Sauté the onion whites and celery until soft
Add the garlic and drained mushrooms and cook another minute
Stir the milk, soup, and sour cream together until smooth; I like to use a whisk.
Reduce the heat to low and add the drained tuna, soup/milk/sour cream, shredded cheese, salt and pepper to the skillet and stir through
Add the cooked noodles and peas to the skillet and stir though gently
Cover and bake for 20 minutes (transfer to a casserole dish if your skillet can’t go in the oven, cover with foil if you don’t have a cover).
Combine the bread crumbs, parmesan cheese and melted butter together.
After 20 minutes, sprinkle the bread crumbs over the top and put it back in the oven uncovered for 5-10 minutes until the crumbs are golden brown.
Garnish with the onion greens.
You can make this a day or two ahead of baking; if you put it into the oven cold, add 15 minutes to the cook time.
Prep 40 minutes, Cook 30 minutes, Serves 4-6