Creamy, comforting, and practical for busy days, this crockpot tuna casserole combines tender egg noodles, savory tuna, peas, mushrooms, and melted cheddar in a rich mushroom sauce. It is a family-friendly slow cooker dinner with simple prep, reliable flavor, and plenty of cozy casserole appeal.
When you want a warm dinner that does not require much attention at the stove, this casserole fits the bill. The noodles soak up the seasoned mushroom sauce while the tuna adds savory flavor and the peas bring a little sweetness to every serving.
The key to getting the texture right is slightly undercooking the egg noodles before they go into the slow cooker. They continue to soften as the casserole cooks, so starting with firm noodles helps prevent them from becoming overly soft.
Cheddar is added near the end rather than at the beginning, giving you a creamy casserole with a fresh layer of melted cheese on top. A sprinkle of breadcrumbs is optional, but it makes a nice finishing touch when you want a little contrast.
Crockpot Tuna Casserole Ingredients
You only need straightforward pantry and freezer ingredients for this comforting dinner.
- Tuna: Three drained 5-ounce cans provide the main savory flavor. Drain the tuna thoroughly so extra liquid does not thin the sauce.
- Egg noodles: Twelve ounces of dry egg noodles create the tender, hearty base. Cook them only until slightly underdone before adding them to the slow cooker.
- Condensed cream of mushroom soup: One 10.5-ounce can forms the creamy foundation of the casserole sauce.
- Chicken broth: Two cups loosen the condensed soup and provide enough moisture for the noodles while adding savory flavor.
- Onion: One cup of diced onion adds depth as it slowly cooks into the sauce.
- Mushrooms: Eight ounces of drained canned sliced mushrooms reinforce the mushroom flavor and provide extra texture.
- Green peas: One and a half cups of frozen peas add color and a mild sweetness. They go in near the end so they do not become overly soft.
- Italian seasoning: Two tablespoons season the creamy base with a convenient blend of dried herbs.
- Salt and black pepper: A half teaspoon of each balances and rounds out the casserole.
- Cheddar cheese: One cup of shredded cheddar is divided between the casserole and its melted topping.
- Breadcrumbs: Up to a quarter cup can be sprinkled over the finished casserole for an optional textured finish.
Step-by-Step Crockpot Tuna Casserole
STEP 1: Bring a large pot of salted water to a boil and cook the egg noodles according to the package directions, but stop before they are completely tender. You want them slightly firm because they will continue cooking once combined with the hot sauce. Drain them very well.
STEP 2: In a large bowl, whisk the condensed mushroom soup and two cups of chicken broth together until the mixture is smooth. Breaking up the condensed soup before adding the other ingredients makes it much easier to coat the noodles evenly.
STEP 3: Stir the drained tuna, diced onion, Italian seasoning, salt, and black pepper into the mushroom sauce. Gently break up any very large pieces of tuna, but avoid overmixing if you prefer noticeable flakes throughout the finished casserole.
STEP 4: Fold the drained, partially cooked egg noodles into the sauce. Transfer everything to your slow cooker, spreading the mixture into an even layer. Cover and cook for 3 to 4 hours on LOW or approximately 1½ to 2 hours on HIGH.
STEP 5: About 15 minutes before serving, stir in the drained mushrooms and frozen peas. Adding these ingredients toward the end keeps the peas brighter and prevents the mushrooms from spending unnecessary hours in the slow cooker.
STEP 6: Stir half of the shredded cheddar into the casserole, then scatter the remaining cheese evenly over the top. Replace the lid and cook for another 15 minutes, or until the cheese has melted and the casserole is piping hot.
STEP 7: If you are using breadcrumbs, sprinkle them over the casserole immediately before serving. They are most noticeable when added at the last moment rather than left to soften under the slow cooker lid.
How to Store & Reheat
Let leftover casserole cool before transferring it to an airtight container. Keep it refrigerated and use it within 3 to 4 days. Because the noodles continue absorbing sauce as the casserole rests, leftovers may be thicker than the freshly cooked dish.
For individual portions, reheating in the microwave is convenient. Heat until thoroughly hot, stirring partway through so the center warms evenly. If the casserole seems dry, stir in a small splash of chicken broth before reheating.
You can also warm larger portions in a covered baking dish in a moderate oven. Adding a small amount of broth before covering helps restore moisture to the noodles.
Freezing is possible, although creamy casseroles containing cooked egg noodles can develop a softer texture after thawing. For the most consistent noodle texture, this dish is better enjoyed fresh or refrigerated rather than frozen. If you do freeze it, store it securely for up to about 2 months and thaw it overnight in the refrigerator before reheating.
Can I put uncooked egg noodles directly in the slow cooker?
For this preparation, it is better to partially cook the noodles first. The recipe’s liquid and cooking time are designed around noodles that have already been boiled until slightly underdone. Starting with completely dry noodles could change both the sauce consistency and final noodle texture.
How do I keep the noodles from getting mushy?
Boil them only until they are slightly underdone, drain them well, and avoid extending the slow cooker time unnecessarily. The noodles continue absorbing liquid during cooking, so starting with firm pasta is one of the most important steps for maintaining a pleasant texture.
Can I use the HIGH setting instead of LOW?
Yes. Cook the casserole on HIGH for approximately 1½ to 2 hours instead of 3 to 4 hours on LOW. Since slow cookers can heat differently, check toward the earlier end of the cooking range and avoid leaving the noodles cooking longer than necessary.
When should I add frozen peas?
Add frozen peas during the final 15 minutes of cooking along with the mushrooms and cheese. They only need enough time to heat through. Adding them at the beginning can leave them much softer and less vibrant by the time dinner is ready.
Are the breadcrumbs necessary?
No. The breadcrumb topping is completely optional. The casserole is already creamy and satisfying without it. If you like a slight contrast against the tender noodles and melted cheddar, sprinkle the breadcrumbs on immediately before serving rather than mixing them into the sauce.
Serving Ideas for Crockpot Tuna Casserole
Because this is already a hearty combination of pasta, tuna, vegetables, and creamy sauce, lighter side dishes work especially well.
- Simple green salad: Crisp lettuce and fresh vegetables provide a refreshing contrast to the creamy noodles.
- Roasted or steamed vegetables: Broccoli, green beans, or asparagus can round out dinner without making the meal feel too heavy.
- Warm bread: A simple piece of crusty bread works well for catching any creamy mushroom sauce left on the plate.
Helpful Tips
- Undercook the pasta slightly. This is the most important texture tip because the noodles continue to soften in the slow cooker.
- Drain canned ingredients thoroughly. Excess liquid from the tuna and mushrooms can make the sauce thinner than intended.
- Save the cheese and vegetables for the end. Adding the peas, mushrooms, and cheddar during the final 15 minutes gives you better texture and freshly melted cheese instead of ingredients that have been cooking for several hours.
T
Crockpot Tuna Casserole
Ingredients
For the Casserole:
- 3 cans tuna 5 oz each, thoroughly drained
- 1½ cups frozen green peas
- ½ teaspoon freshly ground black pepper
- 1 cup onion diced
- 8 oz canned sliced mushrooms drained
- 12 oz dry egg noodles
- 2 tablespoons Italian seasoning blend
- 1 can condensed cream of mushroom soup 10.5 oz
- ½ teaspoon salt
- 2 cups chicken broth for the slow-cooker preparation
For the Topping:
- 1 cup cheddar cheese shredded
- ¼ cup dry breadcrumbs optional
Instructions
- Bring a large pot of salted water to a rolling boil. Add the 12 ounces of egg noodles and cook according to the package directions, stopping when they are slightly underdone and still pleasantly firm. Drain the noodles thoroughly and reserve them. Avoid cooking them completely at this stage, as they will continue softening in the casserole.
- In a large mixing bowl, whisk the condensed cream of mushroom soup with 2 cups of chicken broth until the mixture becomes smooth and evenly blended. Add the drained tuna, diced onion, Italian seasoning, salt, and black pepper, stirring until the ingredients are distributed throughout the sauce. Carefully fold in the partially cooked egg noodles until they are uniformly coated.
- Transfer the prepared noodle mixture to the slow cooker and cover with the lid. Cook on LOW for 3 to 4 hours or on HIGH for 1½ to 2 hours, stirring occasionally when practical, until the casserole is thoroughly heated and the flavors have combined.
- Approximately 15 minutes before the cooking period is complete, remove the lid and gently stir in the drained sliced mushrooms and frozen peas. Add ½ cup of the shredded cheddar cheese and fold it evenly through the casserole. Scatter the remaining ½ cup of cheddar over the surface, replace the lid, and continue cooking for the final 15 minutes, allowing the cheese to melt.
- Once the cheese has melted and the casserole is piping hot, sprinkle up to ¼ cup of dry breadcrumbs over the surface, if using. Serve the casserole hot.