# What You'll Need:
→ Pasta and Fish
01 - 12 ounces egg noodles
02 - 2 cans (5 ounces each) solid white tuna in water, drained
→ Vegetables
03 - 1 cup frozen peas, thawed
04 - 1 cup cremini or white mushrooms, sliced
05 - 1 small yellow onion, finely chopped
06 - 1 cup celery, diced
07 - 2 cloves garlic, minced
→ Sauce
08 - 3 tablespoons unsalted butter
09 - 3 tablespoons all-purpose flour
10 - 2 cups low-sodium chicken or vegetable broth
11 - 1 cup whole milk
12 - ½ cup sour cream
13 - ½ teaspoon kosher salt
14 - ½ teaspoon freshly ground black pepper
15 - ½ teaspoon Dijon mustard
→ Topping
16 - ¾ cup panko breadcrumbs
17 - ½ cup grated parmesan cheese
18 - 2 tablespoons unsalted butter, melted
19 - 2 tablespoons chopped fresh parsley (optional)
# Directions:
01 - Preheat the oven to 400°F. Lightly grease a 9x13-inch baking dish.
02 - Boil egg noodles in salted water until just al dente. Drain and set aside.
03 - Melt butter in a large skillet over medium heat. Sauté onion and celery for 3 minutes. Add mushrooms and cook for 4 minutes until softened. Stir in garlic and cook for 1 minute.
04 - Sprinkle flour over vegetables and stir to coat. Gradually pour in broth, stirring constantly. Add milk and bring to a simmer, cooking until thickened, about 3 to 4 minutes.
05 - Remove from heat and stir in sour cream, Dijon mustard, salt, and pepper.
06 - Fold in tuna, peas, and cooked noodles until evenly combined.
07 - Transfer mixture to the prepared baking dish.
08 - Mix panko, parmesan cheese, and melted butter in a small bowl. Sprinkle evenly over the casserole.
09 - Bake for 20 to 25 minutes until the topping is golden and the casserole bubbles.
10 - Let stand for 5 minutes, then sprinkle with fresh parsley before serving.