It’s a shame, but not a surprise, that braised onion pasta has never achieved avocado toast-like fame. Slow cooked onions are a study in slouchiness, an ode to the texture of mush. Yes, two of the most prominent and indulgent riffs come from two of the world’s late, great food writers — Marcella Hazan, who recommends cooking the onions in lard, and James Beard, whose butter-laden recipe Food52 considers the “highest form of caramelized onions known to man.”

And yet the dish is almost entirely absent New York’s Italian restaurants — almost. I Sodi, a decade-old Tuscan restaurant in the West Village, corrects this allium oversight with a bit of elegant austerity.