This entire dish is right out of Rose and Ruthie's River Café playbook, with just a few tweaks of my own. They taught me how to make fonduta, a silky sauce rich with crème fraîche and egg yolks. It takes less time and just a bit more effort than tomato sauce, and turns a plate of pasta into an elegant and impressive meal. Get yourself some asparagus spears that are as thick as your pointer finger—not those thin or sprouty ones—and you'll enjoy the juicy slivers in each bite.