Easy Tuna Casserole (only 5 ingredients!)

This easy tuna Casserole has become a regular in our dinner rotation — and I mean regular. Five ingredients, one pan, 20 minutes in the oven, and it’s done. The salsa is the secret weapon here, and trust me, it works.

Why You’ll Love It

Only 5 ingredients — rice, corn, salsa, tuna, and cheese. That’s it.
Ready in 20 minutes — throw it together, bake it, eat it.
One pan — barely any cleanup, which on a weeknight is everything.
Mild tuna flavor — the salsa takes the lead, so even picky eaters tend to go back for seconds.
Great leftovers — it reheats well and holds up in the fridge for days.

A Word About the Ingredients

The salsa is doing heavy lifting here, so use one you actually like eating with chips. Sometimes it’s a jar of mid-range grocery store salsa, sometimes it’s a chipotle salsa made from scratch when feeling ambitious. The chipotle version makes the whole thing smokier and a little spicier. Either way works.
Brown rice is what I use. Short grain, when I can find it — the short grain gets this slightly chewy texture in the casserole that I really like. You can use white rice. I won’t tell you not to. But the brown rice holds up better to the baking.
Frozen corn — just defrost it. Put it in a colander and run cold water over it for a minute. Done.
The cheese. Cheddar, shredded. Pre-shredded bags are fine, but freshly grated melts so much better and it only takes about two extra minutes. Do what you want with that information.

A Quick Note on the Tuna

I didn’t used to think about this at all and then I read something about methylmercury in tuna. The upshot is: albacore (the “white” tuna) tends to have more of it, and it’s the kind that accumulates in your body over time rather than just… passing through. The major health organizations have flagged this, and I take it seriously enough now that I reach for skipjack or yellowfin canned tuna instead. They’re nutritionally similar — still full of those omega-3 fatty acids that do good things for your brain and heart and skin — and I just feel better about it. It’s one of those small swaps that costs me nothing extra.

Ingredients

3 cups cooked brown rice (leftover works great — even better, actually)
1½ cups frozen corn, defrosted
1 cup salsa — a good one, one you’d eat straight
1 can tuna (5 oz), drained and flaked — skipjack or yellowfin
1½ cups shredded cheddar, divided

How to Make It

Preheat your oven to 375. While it’s heating, combine the rice, corn, salsa, tuna, and one cup of the cheese in whatever baking dish you’re using. Stir it all together. It’ll look a little chaotic and that’s fine.
Now — and this is a genuine preference thing, not just me being fussy — if you use a 9×12 baking pan, you’ll get a thinner layer that bakes up chewier and a little crispier on the edges. If you use a round or oval casserole dish (a 2.5 quart one works well), it’ll be thicker and a bit juicier. Both are good — the rectangular pan gives you chewy edges, the round dish gives you something saucier. Pick your preference.
Sprinkle the remaining half cup of cheese on top. Bake for 20 minutes.
That’s it. No, really.

Variations

Black beans are a great addition — stir them in with everything else. Adds protein, makes it heartier. Pepper jack instead of cheddar is good if your family likes a little heat.
Cauliflower rice instead of regular rice is possible. It works, but the texture gets a little mushy and you lose that chewiness that makes the original version worth eating. Not something to rush back to.

Storage

It keeps in the fridge for three or four days. Reheat it in a skillet with a tiny bit of butter if you want to bring it back to life — the microwave works but can make the rice go a little gluey. It’s also perfectly decent cold, standing at the counter.

Nutrition (per ¼ of the casserole): around 474 calories, 54g carbs, 28g protein, 17g fat, 5g fiber.

There’s something about this recipe that sounds too simple to be worth making — and then you make it and think, why haven’t I been doing this all along? Five ingredients. One pan. Twenty minutes. It really doesn’t get easier than that.