Quick Recipe Version (TL;DR)
Quick Ingredients
- 12 oz egg noodles
- 2 (5 oz) cans tuna in water, drained
- 1 cup frozen peas
- 3 tbsp unsalted butter
- 1 small yellow onion, finely chopped (about 1 cup)
- 2 celery ribs, finely chopped (about 3/4 cup)
- 3 tbsp all-purpose flour
- 2 cups whole milk
- 1/2 cup low-sodium chicken broth (or more milk)
- 1 tbsp Dijon mustard
- 1 tsp kosher salt, plus more for pasta water
- 1/2 tsp garlic powder
- 1/4 tsp black pepper
- 1/4 tsp sweet paprika
- 1/2 cup sour cream
- 1 cup shredded sharp cheddar cheese
- Topping option A: 2 cups crushed plain potato chips
- Topping option B: 1 cup panko breadcrumbs + 2 tbsp melted butter
Do This
- 1. Heat oven to 375°F. Butter a 9 x 13-inch baking dish.
- 2. Boil noodles in well-salted water until just al dente; drain.
- 3. Sauté onion and celery in butter 6–8 minutes; stir in flour 1 minute.
- 4. Whisk in milk and broth; simmer until thick (3–5 minutes). Season; stir in Dijon, sour cream, and cheddar.
- 5. Fold noodles + tuna + peas into sauce; spread in dish.
- 6. Top with buttered panko (bake now) or add crushed chips during the last 10 minutes so they stay crunchy.
- 7. Bake until bubbling and golden (25–30 minutes). Rest 10 minutes, then serve.
Why You’ll Love This Recipe
- Classic, cozy comfort food with a creamy sauce and a crunchy topping.
- Made from simple pantry staples (tuna, noodles, milk, breadcrumbs or chips).
- One dish, family-friendly, and great for using up freezer peas.
- Flexible: choose potato chips for retro crunch or buttery breadcrumbs for a toasty finish.
Grocery List
- Produce: 1 small yellow onion, 2 celery ribs, fresh parsley (optional)
- Dairy: unsalted butter, whole milk, sour cream, sharp cheddar cheese
- Pantry: egg noodles, canned tuna in water, all-purpose flour, low-sodium chicken broth, Dijon mustard, kosher salt, black pepper, garlic powder, sweet paprika, panko breadcrumbs (optional), plain potato chips (optional)
- Frozen: frozen peas
Full Ingredients
Pasta & Filling
- 12 oz egg noodles
- 2 (5 oz) cans tuna in water, well drained
- 1 cup frozen peas (no need to thaw)
Creamy Celery-Onion Sauce
- 3 tbsp unsalted butter, plus more for greasing the dish
- 1 small yellow onion, finely chopped (about 1 cup)
- 2 celery ribs, finely chopped (about 3/4 cup)
- 3 tbsp all-purpose flour
- 2 cups whole milk
- 1/2 cup low-sodium chicken broth (or use more milk)
- 1 tbsp Dijon mustard
- 1 tsp kosher salt (plus more for pasta water)
- 1/2 tsp garlic powder
- 1/4 tsp freshly ground black pepper
- 1/4 tsp sweet paprika
- 1/2 cup sour cream
- 1 cup shredded sharp cheddar cheese
Topping (Choose One)
- Option A (retro crunch): 2 cups plain potato chips, lightly crushed
- Option B (toasty crumbs): 1 cup panko breadcrumbs + 2 tbsp unsalted butter, melted
Optional for Serving
- 1 tbsp chopped fresh parsley
Step-by-Step Instructions
Step 1: Preheat the oven and prep the baking dish
Arrange a rack in the center of the oven and preheat to 375°F. Lightly butter a 9 x 13-inch baking dish (or a similar 3-quart casserole dish). Set aside.
Step 2: Cook the egg noodles until just al dente
Bring a large pot of water to a boil and salt it generously (about 1 tbsp kosher salt). Add the 12 oz egg noodles and cook to just al dente, following package timing and subtracting about 1 minute (they’ll finish cooking in the oven).
Drain well. Do not rinse.
Step 3: Sauté the celery and onion for a savory base
While the noodles cook, melt 3 tbsp butter in a large skillet or Dutch oven over medium heat. Add the chopped onion and celery. Cook, stirring occasionally, until softened and fragrant, 6 to 8 minutes.
Step 4: Make the creamy sauce (roux, then whisk)
Sprinkle 3 tbsp flour over the vegetables and cook, stirring constantly, for 1 minute to remove the raw flour taste.
Slowly whisk in 2 cups milk and 1/2 cup chicken broth. Bring to a gentle simmer, whisking frequently, until the sauce thickens enough to coat the back of a spoon, 3 to 5 minutes.
Stir in 1 tbsp Dijon mustard, 1 tsp kosher salt, 1/2 tsp garlic powder, 1/4 tsp black pepper, and 1/4 tsp sweet paprika.
Step 5: Finish the sauce with sour cream and cheddar
Reduce heat to low. Stir in 1/2 cup sour cream until smooth, then stir in 1 cup shredded sharp cheddar until melted and creamy.
If your sauce looks extremely thick, loosen it with 2 to 4 tbsp additional milk. You want it creamy and spoonable so the casserole doesn’t bake up dry.
Step 6: Combine noodles, tuna, peas, and sauce
Turn off the heat. Fold the drained noodles into the sauce. Add the drained tuna and 1 cup frozen peas, then gently fold again until evenly mixed (try not to break the tuna into dust; a few flaky pieces are nice).
Spoon the mixture into the prepared baking dish and spread into an even layer.
Step 7: Add topping and bake until bubbling and toasty
If using buttery breadcrumbs (Option B): Mix 1 cup panko with 2 tbsp melted butter until evenly coated. Sprinkle over the casserole.
If using potato chips (Option A): For the crunchiest topping, bake the casserole without chips for the first 15 to 20 minutes, then add 2 cups crushed chips and bake 8 to 10 minutes more. (If you don’t mind a slightly softer chip topping, you can add chips from the beginning—just watch closely for browning.)
Bake uncovered until the edges are bubbling and the top is golden, 25 to 30 minutes total.
Let rest for 10 minutes before serving. Sprinkle with 1 tbsp chopped parsley if you like.
Pro Tips
- Drain the tuna well. Excess liquid can thin the sauce and make the casserole watery.
- Keep noodles slightly undercooked. Al dente noodles soak up sauce as the casserole bakes.
- For maximum crunch, add chips near the end. Potato chips brown quickly and can soften if baked the full time.
- Control thickness. If the sauce gets too thick before mixing, whisk in a splash of milk so the casserole bakes up creamy.
- Season in layers. Taste the sauce before combining; noodles and tuna can mute salt and spice.
Variations
- Mushroom upgrade: Add 8 oz sliced mushrooms and sauté them with the onion and celery until browned.
- No-cheddar classic: Skip the cheddar for a more old-school cream sauce flavor; add an extra pinch of salt and pepper to taste.
- Extra retro topping: Swap chips for 1 1/2 cups crushed butter crackers mixed with 3 tbsp melted butter.
Storage & Make-Ahead
Refrigerate: Cool completely, then cover and refrigerate for up to 4 days. Reheat covered at 350°F for 20 to 25 minutes, or microwave individual portions until hot.
Make-ahead: Assemble the casserole (without potato chips), cover tightly, and refrigerate up to 24 hours. Bake at 375°F for 30 to 35 minutes (it starts cold), then add chips for the last 8 to 10 minutes if using.
Freeze: Freeze tightly wrapped (without chips) for up to 2 months. Thaw overnight in the fridge, then bake at 375°F until bubbling, 35 to 45 minutes. Add chips near the end.
Nutrition (per serving)
Approximate, based on 8 servings and using cheddar plus buttery panko topping: 460 calories; 24 g protein; 44 g carbohydrates; 21 g fat; 9 g saturated fat; 3 g fiber; 820 mg sodium.
