My grandfather made this 3 ingredient meal every spring and it always leaves the plate entirely clean

Every spring when the weather finally started to warm up in the Midwest, my grandfather would make this simple three‑ingredient flounder for Sunday dinner. It’s the kind of no-fuss meal that somehow feels special without requiring a sink full of dishes or a long ingredient list. Just tender, flaky white fish, a salty, crispy cheese crust, and a little butter to bring it all together. It bakes on a foil-lined sheet pan, comes out bubbly and golden, and every single time I make it, the plate is completely wiped clean—just like it was at my grandparents’ table.

This crispy cheese crusted flounder is perfect with simple sides that don’t compete with the rich, salty topping. I like to serve it with roasted or steamed asparagus, green beans, or a quick side salad with a bright vinaigrette to cut through the richness. Buttery rice, garlic mashed potatoes, or a crusty loaf of bread are great for soaking up any cheesy, buttery bits left on the pan. A squeeze of lemon over the top right before serving adds a fresh finish, and if you enjoy wine, a chilled glass of light white wine like Pinot Grigio or Sauvignon Blanc pairs beautifully.

Servings: 4

1 1/2 pounds flounder fillets, thawed if frozen and patted dry

Preheat your oven to 400°F (200°C). Line a rimmed baking sheet with aluminum foil, then lightly coat the foil with cooking spray or a thin drizzle of oil to help prevent sticking.

Pat the flounder fillets very dry on both sides with paper towels. This helps the cheese crust get extra crispy instead of steaming. Lay the fillets in a single layer on the prepared baking sheet, leaving a little space between each piece.

Brush or spoon the melted butter evenly over the tops of the flounder fillets. Make sure each piece gets a light, even coating so the cheese has something to cling to and can crisp up nicely.

Sprinkle the shredded cheese generously over the buttered tops of the fillets, dividing it evenly. Press the cheese very lightly with your fingers so it adheres to the fish, but don’t pack it down too firmly—you want some texture so it can bubble and brown.

Place the baking sheet on the middle rack of the preheated oven. Bake for 10–14 minutes, depending on the thickness of your fillets, until the cheese is melted, deeply golden in spots, and crisp around the edges, and the fish flakes easily with a fork.

If you’d like an extra-deep golden crust, move the pan to the top rack and broil on high for 1–2 minutes at the end of baking, watching closely so the cheese doesn’t burn.

Remove the pan from the oven and let the flounder rest on the baking sheet for 2–3 minutes. This short rest helps the cheese crust firm up and makes it easier to lift the fillets without breaking.

Use a thin spatula to carefully slide under each fillet, keeping the cheese crust intact, and transfer to plates. Spoon any crispy cheese and buttery bits from the foil over the top. Serve immediately while the crust is still hot and crunchy.

Use any firm, mild white fish you have on hand: cod, haddock, pollock, or tilapia all work with the same method and timing (just adjust a minute or two for very thin or very thick pieces). For a slightly different flavor, mix cheeses—try half Parmesan and half sharp white cheddar or Asiago for a deeper, nuttier crust. If you want a touch of seasoning without adding more official ingredients, you can lightly sprinkle the fish with salt and pepper before brushing on the butter, or finish with a squeeze of lemon and a pinch of dried herbs after baking. To make cleanup even easier on a busy weeknight, use heavy-duty foil and fold the edges up into a shallow tray so the butter stays contained. For meal prep, you can arrange the fish on the foil-lined pan and top with cheese up to a few hours ahead; cover and refrigerate, then drizzle with melted butter right before baking. Leftovers reheat best in a hot oven or toaster oven for a few minutes to re-crisp the cheese rather than in the microwave, which can soften the crust.