Jarred piquillo peppers and imported canned tuna from Spain add an Iberian twist to the classic American tuna casserole, making it more elegant but keeping it as simple and quick as the original. Slideshow: More Delicious Casseroles
Preheat the oven to 450°. Cook the farfalle pasta in a large pot of boiling salted water until al dente. Drain.
Meanwhile, in a large saucepan, melt 3 tablespoons of the butter. Add the onion and cook over high heat, stirring, until softened, about 3 minutes. Add the flour and cook, stirring, for 1 minute. Add the milk and bring to a boil. Cook the sauce over moderate heat, stirring occasionally, until thickened, about 3 minutes.
Add the farfalle pasta, frozen baby peas, sliced piquillo peppers, Parmigiano cheese and tuna and season with salt and pepper. Transfer the mixture to a large baking dish, a cazuela (casserole dish) or 4 individual gratin dishes.
In a small skillet, melt the remaining 1 tablespoon of butter. Add the panko and cook over moderate heat, stirring, until golden, about 1 minute. Sprinkle the panko over the casserole and bake for 10 minutes (5 minutes for individual gratins), or until bubbling. Serve right away.
Crisp, medium-bodied Languedoc white.