By Paul Reidinger

WITH THE NEW millennium's many sweeping revisions of reality – failure is now success, war is peace, bullies are ambassadors, 40 is the new 30 – it makes a twisted sort of sense that the new upscale is downscale. Maybe we're all secretly a little tired of upscale anyway; fancy stuff loses its cachet when everybody has it and you can get it for less at Costco or Target or Wal-Mart. What is wanted, upscale-wise, is of course exclusivity: the walling-out of the unwashed, the hoi polloi, those whose tastes, or means, run to beans and rice instead of lobster, caviar, white truffles, foie gras, and the other arteriosclerotic glories of the wealthy table.

It is interesting that grand food is often sickening. Too rich. Even run-of-the-mill restaurant cooking tends to be laden with butter and cream, and who would know this better than restaurateurs? It makes a less twisted sort of sense, then, that the current trend toward street-cart or finger foods would have been launched by proprietors of fancy-feast palaces, from Slanted Door to Butterfly to Maya. One of the more conspicuous of these trickle-down, or trickle-up, endeavors is Mijita, Traci des Jardins's homage to the peasant cooking of her Mexican grandmother.

Mijita (a contraction of mi hijita, "my little daughter") is in the Ferry Building, which rather mutes the street-cred factor. So does the restaurant's emphasis on organic ingredients, but then, des Jardins's career has been, in the main, more about tone than street cred; she cooked at Rubicon in the mid-1990s before launching her own elegant restaurant, Jardinière, in 1997.

Despite the proprietress's high pedigree, Mijita is appealingly not fancy, and it occupies what I would consider one of the choicer spots in the Ferry Building: on the water side, with outdoor seating on a docklike terrace and, through immense plate-glass windows, an intimate view of actual ferry traffic. (It is a relief to see that the historic building still has a working life beyond serving as a set for food porn.) You could never delude yourself that you were in the Mission, but you do order at the counter, take a seat at one of the blond-wood tables with the jumbled plastic chairs, and wait until your number is called and you go to collect your order, which you will find wrapped in butcher paper and arrayed on plastic trays.

If Mijita's prices are a shade higher than those of the Mission (mostly in the $5 to $7 range), the food has an honest, satisfying bluntness that would reassure many a hipster burrito hound. There are no burritos on the menu, as it happens, but there are plenty of worthy substitutes, among them chilaquiles ($6.50 and available only on weekends), an immense plate of Fritos-like fried tortilla strips swimming in a mild, creamy pepper sauce and adjoined by a formidable ladling of refrijoles scattered with shreds of queso blanco. If the pepper sauce strikes you as lacking heat, you can splash in some of the spicier red stuff, Valentina salsa picante (imported from Mexico), from one of the tabletop bottles.

As I have an inexplicable obsession with fish tacos, I was drawn to des Jardins's interpretation of this standard ($4.75). I've had better, frankly; the corn tortillas were a little cold and rubbery, and while the fish was visually striking – a flute of battered, deep-fried mahimahi – the promised avocado-cilantro cream vanished in a bale of shredded green cabbage. Better, because perfectly simple and therefore fail-safe, was a queso fundido ($5), a pot of melted cheese sprinkled with crumblings of chorizo leaking its oily red-orange essence and easily scoopable with steamed tortillas, which were served on the side in a covered tray and were as appealingly soft and alive as those of the fish taco had been lifeless.

Wine note: the house white is Las Brisas, a fabulous blend of verdejo and sauvignon blanc from Spain's Rueda region; it is perfectly balanced between fruit and acid and more substantial – hence better able to stand up to the vigor of the cooking – than such lighter, everyday whites as pinot grigio. If you thought good wine couldn't be matched to Mexican or peasant food, a glass of Las Brisas (it is served in a tumbler) will soon have you thinking otherwise.

We fled the rarefied airs of the Ferry Building for 16th Street and Valencia and a reality check: La Cumbre, which we have long regarded as the city's premier taquería. The reality check wasn't the one we were expecting; instead of being able to compare La Cumbre's offerings with those of Mijita, we found the former temporarily closed, its windows newspapered over. Plan B involved El Toro, a block away but with the same basic drill: queue, steam-tray counter, cashier, salsa station.

Prices can no longer be described as cheap at many of the Mission's better-known taquerías. El Toro's burrito especial – with rice and beans, cheese and choice of meat, plus guac and salsa – set us back $6.95. On the other hand, compared to Mijita, the servings are enormous; an El Toro burrito is twice as big as anything at Mijita – if size matters to you. If it matters adversely, you will welcome the variant known as the "baby" burrito ($4.38) – half the mass of the standard bruiser but still ample and, like its full-grown siblings, full of the zingy flavors of tomatillo, garlic, onion, and chilies. Downsized doesn't have to mean downscale – er, upscale?

Mijita. 1 Ferry Building, #44, S.F. (415) 399-0814, www.mijitasf.com. Mon.-Thurs., 11 a.m.-7 p.m.; Fri., 11 a.m.-8 p.m.; Sat., 9 a.m.-8 p.m.; Sun., 10 a.m.-4 p.m. Beer and wine. American Express, MasterCard, Visa. Noisy. Wheelchair accessible. Taquería El Toro. 598 Valencia (at 17th St.), S.F. (415) 431-3351. Daily, 11 a.m.-10 p.m. Beer and wine. American Express, MasterCard, Visa. Noisy. Wheelchair accessible.