Orecchiette, or pasta resembling “little ears,” is the classic choice for this dish; its cup-like shape is ideal for catching bits of the broccoli rabe. If you can't find orecchiette, campanelle is a good substitute; it cooks in just about the same time. Adding the broccoli rabe in two stages gives the dish textural interest, as some pieces will be fully tender and almost saucy, white others retain a bit of bite. To crush the fennel seeds, pulse a few times in a spice or coffee grinder or use a mortar and pestle. Once everything is in the skillet, the pan will be filled to the brim; the easiest way to stir is with two spatulas and a gentle tossing motion