When concocting the short, seasonal menu at this Mission District restaurant, chef and co-owner Craig Stoll and his partner, Anne, take their cues from simple, regional Italian dishes that allow the talent of the kitchen and the essence of the ingredients to shine through. Making regular appearances on the starters list are an insalata del campo boasting a stand-up, aged balsamic dressing, toasted walnuts and bitter greens; and a plate of succulent grilled calamari resting on frise and warm white beans. Rustic pastas, which are made fresh in-house, make up about half the entre list. Meat and fish command the remainder, with entres such as roast chicken with olive oil mashed potatoes and hanger steak with grilled radicchio, potatoes and anchovy-marrow butter. The mid-size, mid-priced wine list is stocked with tasty bottles, each ideally matched to the menu. Delfina's success is evidenced in the nightly line of well-dressed diners outside the door hoping to get the few coveted walk-in tables. While bar seats for two are usually available on short notice during the week, prime-time weekend reservations may require a call well in advance. But take the 5:30 p.m. reservation if you must; the classy-yet-casual, industrial-inspired, butter-yellow room can get quite noisy by 8 p.m.