Forming an attachment to a restaurant often requires nothing more than falling head over heels for a single dish.

In the case of Mercury Dining Room and Rail and yours truly, that menu item is a boffo chicken salad sandwich.

Yes, this taken-for-granted staple can be more than dry white meat doused in second-rate mayonnaise, on lifeless bread. Chef Jeff Woodyard borrows from the Waldorf salad model, and then gets all the details just right.

First he brines and lightly smokes the bird before roasting it. He selects equal parts breast and thigh, then adds meaty roasted walnuts for crunch, juicy red grapes for pops of sweetness and just enough sage-enriched mayonnaise to bind all the components together.

This mostly meat blend is stacked high onto a nutty whole-grain bread that’s lightly grilled for crunch and sturdiness, and it’s supplemented by tender butter lettuce and tomato slices that are drawn out of their winter coma with tons of salt and pepper. This creature of habit’s daily workday lunch could easily become this habit-forming sandwich. A half is a meal; the whole shebang could easily feed two. Simple pleasures, right?

The restaurant is the latest from Blue Plate Restaurant Co., a portfolio from co-owners Stephanie Shimp and David Burley that also includes the Highland Grill, Edina Grill, Freehouse, 3 Squares and other neighborhood-centric operations. They’ve recognized that, despite downtown’s upward residential growth curve, 5th and Marquette is a different beast from St. Paul’s Highland Park or Maple Grove. Woodyard, a smart hire, has nudged the company’s neighborly, all-day-breakfast mandate into a more slightly upscale position.

Which is why it’s weird that the restaurant, which opened in October, hasn’t developed much of an a.m. audience — not yet, anyway. Because breakfast is when the kitchen really shines.

Straightforward preparations — crisp waffles, well-stuffed omelets, crisp-edged hash browns — are handled with care, and they’re fine. More than fine, actually.

But they’re overshadowed by far more ingenious spins on breakfast classics. Sure, Woodyard is capable of producing a straight-up eggs Benedict at a reasonable price ($11.95, with hash browns), earning full marks for a smoky ham and a spot-on hollandaise.

But why not sub out the English muffin for a soft cornmeal cake, and switch the ham with succulent, slow-braised pork? It’s a delicious idea, and still recognizably a member of the Benedict clan.

A short stack of airy buttermilk pancakes, so straightforward and appealing, are upstaged by slightly sweet cornmeal versions, amusingly dressed with an Elvis Presley-like bananas-and-peanut butter combo. A biscuits-and-pork sausage gravy platter is everything it should be, but I’ve grown to prefer that same flaky, buttery biscuit topped with zesty turkey sausage, fluffy eggs and creamy avocado.

Defying expectations

The something-for-everyone formula is frequently yawn-inducing, but not here. For those craving pot roast, Woodyard sears super-­flavorful center-cut chuck flap, then braises it in beef stock until the meat attains a surprising tenderness.

Roast chicken boasts crispy skin and juicy meat; fried chicken (one of the menu’s many Southern accents) has a suitably crackled-up bite, and scallops are seared to a dark brown yet maintain their whisper of sweetness. Best ever? No. More than suitable? Sure.

The same can be said for the basic desserts, which include a decent brownielike pie with a shortbread crust and a tart lemon tart.

Oysters are becoming semi-ubiquitous, so it’s no surprise that Woodyard is featuring them. But rather than going the cocktail sauce-and-horseradish route, he sneaks in a lively house-cured pork and a colorful basil vinaigrette. Nice.

Now that Macy’s Oak Grill has both feet planted in the departure lounge (its last day is Jan. 27), it’s a relief to see another downtowner pick up the popover gauntlet.

“It’s nice to bring a classic back, and see if it has legs,” he said. “And it does. We sell a lot of them.”

Note the word “sell.” Unlike the Oak Grill, the Mercury popover is not offered gratis, like some time-warp bread basket. They’re sold two for $4.95.

It’s worth it. They’re an airier, crispier version of the Oak Grill popover, with two other distinct (and welcome) differences: They’re gleefully enriched with Cheddar cheese, and served with a mellow garlic butter and a flavorful bone marrow butter, a happy shoutout to the roast beef origins of Yorkshire pudding, the popover’s northern Brit cousin.

Disappointments? Sure. For a guy who spent several decades drawing a paycheck from a major seafood chain (McCormick & Schmick’s), Woodyard’s idea of a crab cake is a sodden, filler-filled shoulder shrug, drowning in a weak mustard sauce. (Crab fans will be much happier with the clean, bright-tasting crab salad, with its echoes of Old Bay seasoning, pops of citrus against creamy avocado and cool, clean lumped blue crabmeat.) Several sloppy appetizers were crying out for a refining hand.

Since the restaurant finds itself in the state’s steakhouse epicenter, it doesn’t seem particularly wise to offer rib-eyes, petite filets and other direct comparisons when others do it better, at approximate prices.

Consistency is also an issue; perhaps the lengthy menu is too much for the kitchen to master. On one visit, I marveled at the merits of a Velveeta-cloaked double cheeseburger (honest, what a beauty), and on another it was as if all of its qualities added up to an out-of-focus smudge of their former glory. Huh?

Sometimes the tweak could be as simple as vigilance. It was a shame that such a pretty and inventive beet/sweet potato salad was drowning in vinaigrette, or that a mammoth beer-battered cod sandwich was so woefully overcooked, and that the kitchen sent them out anyway.

Still, Woodyard’s kitchen is a place where small gestures quickly add up. Kale makes so many cameos that it’s only natural to wonder if the founders of National Kale Day have a stake in the restaurant. But the conceit works, whether it’s providing a foundation for an excellent coleslaw, or it’s slipped into mushroom-filled crêpes, or it’s a creamed-up component in a fried riff on oysters Rockefeller.

Also admirable is how Woodyard routinely caters to diners with dietary restrictions, not by subbing out key ingredients with second-rate replacements (no relying upon tiresome “gluten-free” supermarket products here) but by starting from scratch.

Chicken tacos start with the sandwich’s same thoughtfully prepared bird, then out comes a spiced-up mango salsa, crunchy Napa cabbage, salty queso fresco cheese and packs-a-wallop Fresno chiles. They’re all spooned into delicate, freshly prepared tortillas crafted on the premises with millet and flax, their delicate texture a welcome switch from durable flour tortillas.

And while bowls are being done to death, it’s easy to be impressed by a selection of earthy veggies, each accorded a different treatment (braising, roasting), an umami-laced eggplant-mushroom broth and a runny egg. Perkins, it ain’t.

A slight remodel has erased some but by no means all traces of Brasserie Zentral, the space’s former tenant. The results are certainly less formal, and favor the lighter and brighter end of the design spectrum.

Coming this spring: a walk-up window, aimed at capturing a segment of the warm-weather crowds that swarm the nearby food trucks. Woodyard and his crew are developing a small quick-service menu.

Here’s hoping that chicken salad sandwich will be at the ready.