Instant Pot Tuna Casserole Recipe: No-Drain Pasta with Creamy Sauce

This Instant Pot method revolutionizes classic tuna casserole by eliminating the need to pre-cook and drain pasta separately. The pressure cooker handles everything in one pot, creating a creamy sauce that perfectly coats each noodle without any mushy results.

The key is precise timing—just 4 minutes of pressure cooking transforms uncooked pasta into al dente perfection while the tuna and vegetables meld into the sauce. No watery mess, no extra pots, just a straightforward process that delivers consistent results.

What emerges is a comforting, one-pot meal with tender pasta, flaky tuna, and a rich, creamy sauce that’s ready in under 30 minutes. The flavors develop beautifully under pressure, making this a reliable weeknight solution.

Serve it straight from the pot for an easy, satisfying dinner that requires minimal cleanup.

Ingredients for Instant Pot Tuna Casserole

One pot, no drain, and a creamy sauce that clings perfectly to every noodle.

The cream of mushroom soup is non-negotiable here—Campbell’s is the standard, but any brand works if it’s the condensed variety. The tuna should be in water, not oil (drain it well). For the cheese, sharp cheddar gives the best melty texture, but Colby or Monterey Jack also work. I recommend Whole Foods or Kroger for these staples—their house brands are reliable.

No cream of mushroom? Cream of chicken at half the amount (but check labels for fish derivatives). Fresh peas instead of frozen? Add them at the very end to avoid mush. The broth can be swapped for vegetable if you prefer, but low-sodium chicken broth balances the richness better. The Dijon mustard adds depth—Grey Poupon is my go-to.

Leftovers keep 4-5 days in the fridge—reheats like a dream. Freeze portions for up to 3 months (the sauce may separate slightly but stirs back together). Always use airtight containers to prevent the noodles from drying out.

Step-by-Step Instructions for Instant Pot Tuna Casserole

This method ensures perfectly cooked noodles and a velvety sauce with minimal effort.

Step 1: Sauté Aromatics and Build the Base

Set your Instant Pot to the Sauté function on Normal/Medium heat. Add the 2 tbsp Butter and allow it to melt completely, swirling to coat the bottom of the pot. Once the butter begins to foam, add the 0.5 cup Diced Onion and cook for 3-4 minutes until translucent and just beginning to soften.

Stir in the 2 cloves Minced Garlic and 0.5 tsp Dried Thyme, cooking for an additional 30 seconds until the garlic becomes fragrant. Be careful not to let it brown—this prevents bitterness. Immediately sprinkle the 2 tbsp All-Purpose Flour over the mixture and whisk vigorously for 1 minute to create a smooth roux that will thicken your sauce.

Step 2: Deglaze and Add Liquids

Slowly pour in the 2 cups Chicken Broth while whisking constantly to prevent lumps from forming. Scrape the bottom of the pot thoroughly with a wooden spoon to release any browned bits—this adds depth of flavor to your casserole. The mixture should begin to thicken slightly as it comes to a gentle simmer.

Add the 1 can Cream of Mushroom Soup, 1.5 cups Milk, 1 tbsp Dijon Mustard, 0.5 tsp Salt, and 0.25 tsp Black Pepper. Whisk until completely smooth and homogeneous. The sauce should have a creamy, velvety texture at this stage. Taste and adjust seasoning if needed, though remember the flavors will concentrate slightly during pressure cooking.

Step 3: Incorporate Pasta and Protein

Break the 8 oz Egg Noodles in half so they fit better in the Instant Pot, then add them to the pot, pressing down gently to submerge them in the liquid. Stir in the 2 cans Canned Tuna (drained) and 1 cup Frozen Peas—there’s no need to thaw the peas first as they’ll cook perfectly during the pressure cycle.

Ensure all noodles are fully submerged in the liquid. If any are sticking up, press them down gently. The liquid should just cover the noodles—if it seems insufficient, add a splash more chicken broth to prevent burning. This step is crucial for even cooking and preventing the dreaded “Burn” notice on your Instant Pot.

Step 4: Pressure Cook to Perfection

Secure the lid on your Instant Pot, making sure the valve is set to Sealing. Cook on High Pressure for 4 minutes. The pot will take approximately 10-12 minutes to come to pressure before the cooking time begins.

Once the cooking cycle completes, allow the pressure to release naturally for 5 minutes, then carefully switch the valve to Venting to release any remaining pressure. The noodles should be perfectly al dente, and the sauce will have thickened considerably, coating the back of a spoon.

Step 5: Finish with Cheese and Rest

Open the lid and stir in the 1 cup Shredded Cheddar Cheese until fully melted and incorporated. The sauce will become even creamier and more luxurious. If the casserole seems too thick, stir in a small amount of warm milk to reach your desired consistency.

Let the casserole rest for 5 minutes before serving. This allows the sauce to set slightly and the flavors to meld together. The final result should be a rich, creamy tuna casserole with perfectly cooked noodles and a velvety sauce that clings to every bite.

Dietary Considerations for instant pot tuna casserole

Gluten-Free Adaptation

Swap the 8 oz Egg Noodles for gluten-free pasta like Barilla or Jovial brown rice noodles. Reduce pressure cooking time to 3 minutes since gluten-free pasta cooks faster. Check for doneness immediately to avoid mushiness. 💪

Dairy-Free Version

Replace whole milk with unsweetened almond milk and use dairy-free cheddar like Violife. The cream of mushroom soup can be swapped for a dairy-free alternative. Add 1 tbsp nutritional yeast for a cheesy flavor boost.

Lower-Carb Option

Use zucchini noodles or shirataki noodles instead of egg noodles. Add them after pressure cooking with the cheese, as they only need 2-3 minutes to heat through. The sauce will be just as creamy and satisfying.

Allergen Notes

This dish contains fish (tuna), dairy, and gluten in its original form. For nut allergies, ensure your broth and soup are nut-free. Always check labels on canned goods for hidden allergens.

Lightened-Up Version

Use low-fat milk and reduced-fat cheese to cut calories. Swap cream of mushroom soup for a low-fat version. You’ll still get a creamy texture with fewer calories per serving. 💡

Pescatarian Friendly

This dish fits perfectly into a pescatarian diet as written. For extra protein, add ½ cup cooked shrimp or chopped scallops along with the tuna. The flavors complement each other beautifully.

Frequently Asked Questions