The upper-west level of Pasadena's Paseo Colorado complex is a catalog of mild modern sins, a promenade of cigar stores, wine bars and tea shops, crystal-laden boutiques and holistic-massage parlors, overlaid by a thin film of hot suburban lust. Fitting right in is the new Brazilian churrascaria Porto Alegre, a yawningly huge palace of the basest carnal appetites. Here, dripping rump roasts carved to order from superheated metal swords, fennel-laced sausages and plump chicken legs, crisp-skinned quail and fat prime rib, bacon-wrapped filets and an incongruous side of baked salmon are slipped onto your plate until you grab a waiter's lapels and shriek "Stop!"There is an enormous salad bar, of course, stocked with smoked salmon, prosciutto and hearts of palm as well as the usual suspects, and warm balls of cheese bread that expand in your belly like some magical diet aid - the establishment wants your stomach to be full for your $35.50 prix fixe. Porto Alegre is neither L.A.'s best churrascaria (that would be Fogo de Chao), its sexiest (By Brazil in Torrance), nor its sleekest (probably Burbank's Picanha). Its sisters, the massive Green Field restaurants in Covina, Long Beach and Queens, far surpass it in grandeur. Gaucho's Village in Glendale is homier. But in a mall whose other choices run to Tokyo Wako, Islands and P.F. Chang's, Porto Alegre might as well be the greatest restaurant in the world.