Shortly after Tia Pol opened, it became evident that the cramped, wildly popular tapas joint was going to need to expand if it hoped to accommodate all of its would-be customers. Three years later, the owners have at last opened a new restaurant, just a couple of blocks from the first, serving an even simpler version of the simple, often exquisite Spanish food that made Tia Pol a hit.

But, in a move that’s true to the spirit of the nook-like bars of Spain, El Quinto Pino, the new spot, is even less roomy than the old one. I showed up there at 6:30 p.m. early in the week, and it was like a rush-hour train car, with well-dressed young couples and workmates vying for space at the standing-room-only counter; the handful of bar stools were long since claimed. There are no tables. The counter, which runs the circumference of the small room, can accommodate perhaps 25 people sitting shoulder to shoulder; on my visit I counted 40 people in the room, many just packed into the middle, clutching glasses and making the lone waiter’s unenviable job that much harder.

The menus of food and drink are written on chalkboards above the bar, with a pillar positioned so that, from most vantage points, one menu or the other is obscured. They don’t make it easy. Fortunately, there are only a dozen or so food choices, and with prices averaging around $9, a misstep isn’t dire. There are little discrete snackables, such as good green olives ($3), sweet, creamy-tasting Marcona almonds ($3), and two kinds of anchovy: Fileted boquerones ($12) are marinated in vinegar and served in oil with rounds of bread to messily fork them onto; you can do the same with Basque-style anchoas de Ondarroa ($11), which are cured in oil so they’re stiff and luxuriously piquant. Be sure to scoop some of the olive-oily tomato purée onto the bread too. Both are great, simple options, but I’d opt for the Basque variety more often. Crisp, expertly battered fritters filled with moist salt cod ($7.50) feel a little stripped-down, with no dipping sauce to complement their salty fried simplicity — or perhaps the little, rushed kitchen just forgot to include aioli the night I tried them. Conversely, a plain-sounding dish of shrimps in garlic sauce ($9) gets a dose of unexpected, quasi-Asian excitement from an abundance of fresh ginger.

The casual snack-bar theme is played to the hilt in presentations, such as the rumpled brown paper bag in which the restaurant serves torreznos, simple, unapologetically greasy little hunks of fried pork rind. With a wink, three slender hot sandwiches come packaged as though for take-out in wax-paper bags — each garnished with one of the restaurant’s business cards. The sandwiches are by far the high points of El Quinto Pino, in particular the sea-urchin sandwich ($15), which has already amassed a fan base. Chewy, thin French loaves are halved and slathered with butter and lots of the custardy, aquatic-tasting meat of the urchin. It gets a burst of sinus-clearing heat from a drizzle of mustard oil, reminiscent of the wasabi that pairs with sea urchin in its natural habitat, sushi. Each messy bite is refreshing and luxurious and addictive, a little feast of marine tang, richness, and pungency.

The other sandwiches can’t live up to that, but they do pretty well: Pringa ($7) is a delightful hot mélange of juicy, pulled braised meats with a confit-like smear of rich blood sausage on sturdy, flavorful bread. Serrano ham ($7) makes for a particularly gamy ham sandwich; delightful for true pork fans but perhaps a bit strong for the casual eater.

The third link in the Tia Pol-Quinto Pino chain is a Spanish wine shop in the East Village, Tinto Fino, so it’s no surprise that the restaurant is well-equipped with drinks: There is a short but satisfying list of Spanish wines, including a beautifully rounded, soft Rioja from Izadi ($12/glass) and a nice choice of cavas. There’s also a slushy, brandy-spiked version of horchata, the refreshing nut milk ($9), which makes a better dessert than the gummy pastry that’s offered ($5), and a zingy frozen lemonade invigorated with basil and gin.

El Quinto Pino is a type of establishment that’s not easily placed in any of the standard New York categories. It behaves like a bar, it cooks like a restaurant, and it feels like a subway. But an openness to multiple roles isn’t a disadvantage: You can stop in for just a drink or a late-evening fortification, or compose a whole dinner of delicious small bites if you can bear the jostling.