Fish Roulades with Cheese, Spinach, and Tomatoes

Gut the flounder carcasses, remove the heads, trim the fins, and fillet them by removing the bones.

Pat the fillets dry with paper towels, season with salt and pepper, and spritz with lime juice.

Finely dice the onion and garlic, and sauté them in butter.

Dice the tomatoes, coarsely grate the cheese, finely chop the spinach and green onion, and mix all the ingredients together.

Place the fish fillets skin-side down, spoon the filling onto the wider end, and carefully roll them up.

Arrange the roulades on a baking sheet lined with parchment paper, brush the fish with butter on top, and bake in a preheated oven at 180 °C (350 °F) for 30–35 minutes.