By LESLIE BRENNER When a chef approaches something  with passion, it’s always fascinating to see where it goes. That’s why dinner at Casa Rubia, the new tapas place in Trinity Groves, can be so rewarding. The benefits might start coming to the table in the form of croquetas de maiz, corn-and-chorizo fritters that pick up even more deliciousness with a swipe of charred oregano aioli. Or buñuelos de pollo — hot, savory doughnuts whose creamy insides are rich with chicken and bits of jamón Serrano. The thick crema of Valdeón blue cheese in the bottom of their bowl makes a lovely sauce. The dining room’s focal point, a graphically striking mural of kaleidoscopic images of the ceiling of Gaudi’s Sagrada Familia basilica in Barcelona, expresses the restaurant’s aesthetic perfectly: audaciously Spanish modern. And that’s the passion chef Omar Flores is exploring and expressing in the kitchen. You might know Flores and his co-owner, Jonn Baudoin, from Driftwood, Baudoin’s Bishop Arts seafood place. At Casa Rubia, they’re taking Spain’s small plates beyond the much more modest ambitions of traditional Dallas tapas bars such as Cafe Madrid or Sí Tapas Restaurant Bar. With its all-Spanish wine list, top-notch, well-informed service, and vibrant dining room designed by Stefania Morandi (who also designed Trinity Groves’ Souk and Four Corners Brewery), it’s a very exciting new restaurant indeed. Oh, and there’s a full complement of sherries — the nicest thing, in my opinion, to drink with tapas. An evening that starts with a copita of Valdespino Inocente Fino or Lustau Península Palo Cortado is bound to be a good one. For the most part, Flores’ cooking here is as sophisticated as it has been in the past at Driftwood, and the majority of the tapas — those listed on the frequently changing menu as “complex” — are just as formal as Driftwood’s plates. Mostly, they are wonderful. Those who love their big bowls of steamed mussels would do well to try Flores’ mejillones en escabeche. Removed from their shells, the small, sweet and tender cooked Cape Cod mussels benefit from a bath in a marinade of sour orange, sherry vinegar and herbs. Artfully arranged with delicate mounds of trout roe and punctuated with tiny house-made potato chips for crunch, it’s splendid. So are the alcachofas — crisply fried baby artichokes layered with moist shards of mojama (Spanish-style salt-cured tuna) and arranged around a silken saffron aioli. Fresh mint leaves and a touch of chile pull the flavors into brilliant focus. Curls of lardo ibérico, herb-scented salt-cured fatback, wrapped around chunks of pickled radish, make an excellent tapa, too. Meanwhile, the flavor of Flores’ tender and sublimely lamby cordero — lamb belly, in this case — took me back to Ribera del Duero, where the regional specialty is baby lamb roasted to tenderness in clay ovens. The chef pairs the meat with ethereally soft parsnip purée; pomegranate seeds and a zing of pomegranate molasses give it Moroccan flair. A number of the plates, while certainly delicious, are harder to share, requiring knife-and-fork surgery or the careful transport of dabs of sauce that can get in the way of what’s supposed to be tapas’ relaxed, grab-a-bite charm. A terrific bacon-wrapped ballotine of rabbit (three slices) on lentils with dabs of smoked egg purée would have been perfect had we been three, but we were four. Same issue with an otherwise marvelous, crisp-skinned quail filled with a farce of Tuscan kale and merguez sausage, set off by crunchy sunchokes and rings of pickled red pearl onion. A rich, smoked onion- chicken sauce rounded out the flavors beautifully, but the dish was better-suited for one (yes, me). Platters of cheese or embutidos, cured meats, counterbalance the more elaborate plates. The deep-pocketed might spring for an order of jamón ibérico de bellota ($25). Spain’s most prized ham comes from black-footed pigs that eat only acorns, and the cured meat has a fabulous nutty flavor and superb richness. Lomo ibérico de bellota, more affordable slices of loin ($14), are nearly as fabulous. Both come with a stack of smoky, crusty toasted bread doused with olive oil. Left naked, the bread would work better with those unctuous meats. The paellas del día were much less successful than the tapas, as was an expensive ($65) off-the-menu special one night, a six-bone rack of lamb that came to the table not medium-rare as the waiter suggested, but so rare my guests were put off. It came with a bowl of Moroccan-spiced chickpeas laced with pine nuts and kale that was fine, but nothing special. Diners at the next table warned us away from the paella one night, and they were right. The $55 dish, meant to serve four or more, was terrible: oily, hard and Spartanly garnished with bits of pork, kale and rutabaga. Another night it was much better, though again, a bit oily. This one, reddish-brown with paprika, was studded with sweet little clams, mussels, chicken and diced rutabaga and topped with seared scallops and charred scallions. It was served with a lemony, glossy, squid ink aioli so good I ate it by the spoonful. I kept trying to love the desserts — or at least like them — but their modernist fussiness came off as more pretentious than delicious, and one that features torrijas — Spain’s version of French toast — tasted as though it had been fried in old oil. Best was a roasted-pineapple sorbet with a strap of lime curd, though its toasted coconut crumbs, crunchy rafts of frozen white chocolate mousse and dots of pineapple gel elevated it not a bit. I may have lost patience with the fad, but these desserts don’t argue in its favor. Anyway, you can skip dessert, and instead end an evening at Trinity Groves’ most appealing new place with a plate of good Spanish cheeses. With the Spanish red left in your glass — maybe a 2009 Alejandro Fernández El Vínculo from La Mancha, or a 2010 Bodegas Pujanza Hado Rioja — it makes a fine finish. With a glass of sherry, maybe a Lustau Don Nuño Dry Oloroso, it makes a memorable one. Follow Leslie Brenner on Twitter at @lesliebrenner. Casa Rubia (4 stars) Price: $$$ (“simple” tapas $5 to $8; cheese or cured-meat plates $7 to $36; “complex” tapas $10 to $17; desserts $8.50) Service: Professional and well-informed about the menu Ambience: A vibrant dining room with an open kitchen, inviting bar, comfortable banquettes and a striking kaleidoscopic mural Noise level: Tolerable on nights when the restaurant isn’t packed, but the cacophony can be trying on a night when it is. Location: Trinity Groves, 3011 Gulden Lane, Dallas; 469-513-6349; Hours: Monday-Thursday 5 to 10 p.m., Friday-Saturday 5 to 11 p.m. Reservations: Accepted Credit cards: All major Wheelchair accessible: Yes Alcohol: Full bar, with a well-chosen (if overpriced) all-Spanish wine list and an excellent selection of sherries