It isn’t the unapologetically traditional menu that distinguishes I Sodi, or its spare, classic design. It’s not the eight riffs on the negroni cocktail, or the deep Italian wine list, or the civilized, civilizing mood of the room, which is convivial but never cacophonous. It isn’t even the signature lasagna, which you’ll see some nights at every other place setting — a tall construction of crisp-edged sheets melded together into a supple, jiggly mass. It is all of those things combined, filtered through the singular vision of Rita Sodi, a self-taught chef who opened the place as an extension of her own home table and a tribute to her mother’s country-Tuscan cooking. On paper, the food seems generic — a grilled strip steak, cacio e pepe, branzino. But everything is carefully cooked, restrainedly seasoned, and tasting precisely of what it is, down to the soft-bordering-on-mushy (in proper Italian fashion) spinach and peas. The bar is always full, and though the occasional celebrity has been known to frequent it, so do locals who are happy to keep it to themselves.