Rossejat de fideus is similar to paella, but instead of rice uses slender noodles that have been toasted until richly browned. We use capellini pasta (also called angel hair) and break it by hand into rough 1-inch pieces (do this over a bowl to keep the pieces contained). Toasting brings out the nutty-wheaty notes of the pasta, which then is simmered in broth instead of water. You will need a broiler-safe 12-inch skillet for this recipe, as the noodles are first cooked on the stovetop, then browned under the broiler. This dish is traditionally served with aioli, a garlicky mayonnaise; we make a quick, extra-lemony version using store-bought mayonnaise.