Creamy Tuna Noodle Casserole with Peas

Why You’ll Love This Recipe

• From-scratch creamy sauce—no canned soup needed.
• Pantry-friendly and budget-wise, yet deeply comforting.
• Golden, buttery crumb topping adds the perfect crunch.
• Weeknight-easy: one skillet for the sauce, one pot for noodles.

Grocery List

• Produce: Yellow onion, garlic, fresh parsley, lemon (optional)
• Dairy: Unsalted butter, whole milk, Parmesan (optional)
• Pantry: Egg noodles, canned tuna, frozen peas, chicken or vegetable broth, all-purpose flour, breadcrumbs, Dijon mustard, kosher salt, black pepper

Full Ingredients

For the Casserole

• 12 oz wide egg noodles
• 2 cans (5 oz each) solid light or albacore tuna in water, drained and flaked (about 10 oz drained)
• 1 cup frozen peas

For the Creamy Sauce

• 4 tbsp unsalted butter
• 1/2 cup finely chopped yellow onion (about 1/2 medium)
• 2 garlic cloves, minced
• 1/4 cup all-purpose flour
• 1 1/2 cups whole milk
• 1 cup low-sodium chicken or vegetable broth
• 1 tsp Dijon mustard
• 2 tsp fresh lemon juice (optional, brighten the flavors)
• 1 tsp kosher salt, plus more to taste
• 1/2 tsp freshly ground black pepper

Buttered Crumb Topping

• 1 cup plain or panko breadcrumbs
• 2 tbsp unsalted butter, melted
• 2 tbsp finely grated Parmesan (optional)
• Pinch of kosher salt

For Serving

• 2 tbsp chopped fresh parsley
• Finely grated lemon zest or lemon wedges (optional)

Step-by-Step Instructions

Step 1: Heat the oven and start the noodles

Preheat the oven to 375°F (190°C). Grease a 9×13-inch baking dish. Bring a large pot (at least 4 quarts) of well-salted water to a boil. Cook the egg noodles until just shy of al dente—about 2 minutes less than the package time. Drain well and set aside.

Step 2: Sauté the aromatics

In a large, deep skillet or saucepan, melt 4 tablespoons of butter over medium heat. Add the chopped onion and cook, stirring, until translucent and tender, 3 to 4 minutes. Stir in the minced garlic and cook until fragrant, about 30 seconds.

Step 3: Make the roux

Sprinkle the flour over the onions and garlic. Cook, stirring constantly, for 1 to 2 minutes to eliminate the raw flour taste. The mixture will be thick and pasty.

Step 4: Build and season the sauce

Gradually whisk in the broth, then the milk, whisking until smooth. Bring to a gentle simmer and cook, stirring, until the sauce thickens enough to lightly coat the back of a spoon, 3 to 4 minutes. Stir in the Dijon, salt, pepper, and lemon juice if using. Taste and adjust seasoning.

Step 5: Fold in tuna, peas, and noodles

Remove the pan from heat. Add the peas and flaked tuna, gently folding to keep some tuna chunks intact. Add the drained noodles and toss until everything is evenly coated. If the mixture seems too thick, stir in 2 to 4 tablespoons of milk to loosen.

Step 6: Assemble with buttered crumbs

Transfer the mixture to the prepared baking dish, spreading it into an even layer. In a small bowl, combine the breadcrumbs, melted butter, a pinch of salt, and Parmesan if using. Sprinkle the crumbs evenly over the top of the casserole.

Step 7: Bake, rest, and serve

Bake uncovered until the topping is golden and the edges are bubbling, 20 to 25 minutes. Let the casserole rest for 10 minutes to set. Garnish with chopped parsley (and a little lemon zest, if you like) and serve warm.

Pro Tips

• Boil the noodles slightly under al dente so they finish perfectly in the oven.
• Whisk the liquid in gradually to avoid lumps and ensure a silky sauce.
• Drain tuna very well; excess liquid can thin the sauce.
• If the topping browns too quickly, tent loosely with foil for the last 5 minutes.
• Add a splash of milk when mixing if the casserole looks too dense before baking.

Variations

• Cheesy bake: Stir 1 cup shredded sharp cheddar into the sauce before adding noodles.
• Mushroom celery mix-in: Sauté 1 cup sliced mushrooms and 1/2 cup diced celery with the onion.
• Gluten-free: Use gluten-free egg noodles, gluten-free breadcrumbs, and a 1:1 gluten-free flour blend.

Storage & Make-Ahead

Refrigerate leftovers, tightly covered, for 3 to 4 days. Reheat in a 350°F oven, covered, for 15 to 20 minutes; add a splash of milk if needed to revive the sauce. Microwave individual portions until hot. To make ahead, assemble the casserole up to the topping, cover, and refrigerate up to 24 hours. Top and bake when ready. To freeze, assemble fully (uncooked), wrap well, and freeze up to 2 months. Bake from frozen at 375°F, covered, for 45 to 55 minutes, then uncover for 10 minutes to crisp the crumbs.

Nutrition (per serving)

Approx. 490 calories; 19 g fat (10 g saturated); 58 g carbohydrates; 26 g protein; 3 g fiber; 780 mg sodium. Nutrition values are estimates.