# What You'll Need:
→ Pasta & Fish
01 - 12 oz wide egg noodles
02 - 2 cans (5 oz each) tuna in water, drained and flaked
→ Vegetables
03 - 1 cup frozen peas
04 - 1 cup diced celery
05 - 1 cup diced white or yellow onion
06 - 1 cup sliced white mushrooms (optional)
→ Sauce
07 - 2 tablespoons unsalted butter
08 - 2 tablespoons all-purpose flour
09 - 2 cups whole milk
10 - 1/2 cup sour cream
11 - 1 can (10.5 oz) condensed cream of mushroom soup
12 - 1/2 teaspoon kosher salt
13 - 1/2 teaspoon black pepper
14 - 1/2 teaspoon garlic powder
15 - 1/2 teaspoon dried thyme
→ Topping
16 - 1 1/2 cups crispy fried onions
17 - 1/2 cup shredded cheddar cheese (optional)
# Step-by-Step Guide:
01 - Preheat oven to 375°F. Lightly grease a 9x13-inch baking dish.
02 - Boil egg noodles in salted water until al dente. Drain and set aside.
03 - Melt butter in a skillet over medium heat. Add diced onion, celery, and mushrooms if using; sauté for 4 to 5 minutes until softened.
04 - Stir in flour and cook for 1 minute. Gradually whisk in milk and simmer, stirring, until slightly thickened, about 2 to 3 minutes.
05 - Add sour cream, cream of mushroom soup, salt, pepper, garlic powder, and thyme. Stir until smooth and heated through.
06 - Fold drained tuna, peas, and cooked noodles into the sauce until evenly combined.
07 - Transfer mixture to prepared baking dish. Sprinkle with cheddar cheese if desired, then top with crispy fried onions.
08 - Bake uncovered for 25 to 30 minutes until bubbling and golden on top.
09 - Allow casserole to rest for 5 minutes before serving.
