This 5-ingredient oven baked undrained tuna is the kind of weeknight pantry dinner that saves the day when the fridge looks empty and everyone is still expecting something warm and filling. Using canned tuna packed in oil without draining it adds flavor and keeps the casserole from drying out, while a few basic shelf-stable ingredients turn it into a simple baked meal with very little prep. It has that practical, old-school casserole feel that makes sense for busy nights, especially when you want something inexpensive, comforting, and surprisingly satisfying.
Serve this tuna bake with a crisp green salad, steamed broccoli, roasted green beans, or simple buttered peas to balance the rich, savory filling. If you want to stretch it further, add toasted bread, garlic toast, or spoon it over hot rice or cooked egg noodles. A squeeze of lemon at the table also brightens everything up nicely.
5-Ingredient Oven Baked Undrained Tuna
Servings: 4
Ingredients
2 cans (5 ounces each) tuna in oil, undrained
1 cup uncooked white rice
2 cups water
1 can (10.5 ounces) condensed cream of mushroom soup
1 cup shredded cheddar cheese
Directions
1. Preheat the oven to 375°F and lightly grease an oven-safe glass casserole dish.
2. Add the undrained tuna, uncooked rice, water, condensed cream of mushroom soup, and half of the shredded cheddar cheese to the casserole dish. Stir well to break up the tuna and evenly combine everything.
3. Cover the dish tightly with foil and bake for 35 to 40 minutes, or until the rice is tender and most of the liquid has been absorbed.
4. Uncover, sprinkle the remaining cheddar cheese over the top, and return the dish to the oven for 5 to 10 minutes until the cheese is melted and lightly golden.
5. Let the casserole rest for 5 minutes before serving so it sets up slightly, then scoop and serve warm.
Variations & Tips
Add peas: Stir in 1 cup of drained canned peas or frozen peas before baking if you want a more classic tuna casserole feel and a little extra color.
Use a different soup: Cream of celery or cream of chicken can be swapped for cream of mushroom if that is what you have in the pantry. The texture stays creamy and the flavor changes just a little.
Check the rice: Baking time can vary a bit depending on the depth of your casserole dish and the brand of rice. If the rice is still firm, add a splash of hot water, cover again, and bake a little longer.
Make it crispier: For a more browned top, place the casserole under the broiler for 1 to 2 minutes after the cheese melts, but watch it closely so it does not burn.
Meal prep tip: Leftovers keep well in the fridge for up to 3 days. Reheat covered in the microwave or oven with a spoonful of water if needed to loosen the texture.