L'Osteria del Forno might be only slightly larger than a walk-in closet, but it's one of the top three authentic Italian restaurants in North Beach. Peer in the window facing Columbus Avenue, and you'll probably see two Italian women with their hair up, sweating from the heat of the brick-lined oven, which cranks out the best focaccia (and focaccia sandwiches) in the city. There's no pomp or circumstance: Locals come here strictly to eat. The menu features a variety of superb pizzas, salads, soups, and fresh pastas, plus a good selection of daily specials (pray for the roast pork braised in milk), which includes a roast of the day, pasta, and ravioli. Small baskets of warm focaccia keep you going until the arrival of the entrees, which should always be accompanied by a glass of Italian red. Good news for folks on the go: You can get pizza by the slice.