The key ingredient in this dish? The lobsters’ coral, or roe sac, which lends a briny tang to this vibrant pasta, and ensures that you leave no part of the lobster to waste. Lobster meat itself is relatively mild; adding some roe imbues the sauce with the very essence of lobster. But no worry if you can't find it; feel free to substitute another kind of roe, such as sea urchin or cod roe. Japanese cod roe, often called mentaiko, would be especially good here, as it's made with chile that can support the pasta's kick.