Mucca Osteria, which opened five years ago, is a pocket of suburban decor with brick walls, ornate mirrors and a sepia-tinted map of Italy located on a downtown Portland block better known for rumbling MAX trains and inexpensive Mexican food. Yet this was the restaurant most often mentioned as an oversight in last year's best restaurant guide. That Mucca has survived, thrived even, is a testament to chef Simone Savaiano, a native of Rome who left behind restaurants in Italy, moved to the United States and eventually settled in Portland. Consider his leaning-tower Caprese salad, or the credit-card-thin discs of rare lamb carpaccio. On a recent visit, Savaiano's Lombata di Maiale, a fatty, salt-crusted slab of pork shoulder with figs, sauteed kale, polenta and a balsamic reduction, was cooked just about perfectly, retaining a rosy blush. Later, there was the pleasure of an espresso-rich tiramisu and the last drops of an inexpensive Chianti.