Preheat the Oven

• Preheat your oven to 375°F (190°C). Grease a 9×13-inch baking dish and set aside.

Cook the Noodles

• Cook the egg noodles in salted boiling water until al dente, according to package instructions. Drain and set aside.

Sauté the Vegetables

• In a large skillet, melt the butter over medium heat.
• Add the chopped onion and celery, and sauté for 5-7 minutes until softened.
• Stir in the garlic and cook for 1 minute until fragrant.

Make the Creamy Sauce

• Sprinkle the flour over the sautéed vegetables and stir to combine. Cook for 1-2 minutes to eliminate the raw flour taste.
• Gradually whisk in the chicken or vegetable stock, milk, and heavy cream. Bring to a simmer and cook for 5 minutes, stirring constantly, until the sauce thickens.
• Remove the skillet from heat and stir in the cheddar cheese, Parmesan cheese, salt, and black pepper until the cheese melts.

Combine the Ingredients

• In a large mixing bowl, combine the cooked noodles, flaked tuna, and creamy sauce. Mix gently until well coated.

Assemble the Casserole

• Transfer the mixture to the prepared baking dish, spreading it evenly.
• In a small bowl, combine the breadcrumbs with olive oil. Sprinkle the breadcrumb mixture evenly over the casserole.

Bake the Casserole

• Bake in the preheated oven for 25-30 minutes, or until the top is golden and the casserole is bubbling around the edges.

Garnish and Serve

• Remove from the oven and let it cool for 5 minutes. Garnish with chopped parsley and serve warm.