By 7:30 p.m. on this Friday, there was no one left in the big downstairs market where, by day, the busy cafeteria sells house-smoked barbecue, amazingly flaky chicken potpies, and those sugar-dusted doughnuts by the thousands - often to weekend cyclists on a convenient "power break" from their bucolic jaunts.

I headed upstairs to the old hayloft, where I was the first to arrive at the "chef's table" recently launched by Northbrook's new owners. The massive table, a 22-seat behemoth hewn on-site from pine and oak trees struck down by lightning, was prettily set with flowers for the nine-course BYOB feast. But who, I wondered, would be joining me this Friday night?

Unlike the wildly popular Talula's Table, another daytime market with nightly chef's tastings in nearby Kennett Square, where the private meals are reserved by whole smaller parties, Northbrook's fledgling dinners (and much larger table) can be a hodgepodge affair cobbled together from assorted groups.

They've catered to as few as two, as they did on a slow weekday night when a friend and I were outnumbered by the staff - one charming server plus co-owner/chefs Guillermo Tellez and Rob Boone, who personally presented each seasonally inspired dish. From the bite-size cubes of Gallia melon wrapped in prosciutto and topped with a brulee crisp of smoked sugar to seared scallops over Israeli couscous studded with pomegranate and pumpkin to a tender duo of venison and pork over purees of gingered collard greens and dried plums, it was a memorably decadent meal, the height of intimate fine-dining in the rustic heart of farm-country chic.

Or, your small party could find itself appended to a much larger one, as we did on this particular Friday, when a group of 19 horse-country aristocrats arrived for a birthday party to unexpectedly find three interlopers from the big city at their table.

"And you are . . . ?" was the tepid reply I received when greeting my perplexed new dining companions. Most of whom, I learned, dabbled with horse farms nearby.

It was an awkward start. But then, eating under an alias (as I always do) can be stifling when it comes to dinner chitchat with strangers. Things warmed considerably with the arrival of my own late guests, the singers Phil Roy and Melody Gardot, whose gregarious nature and talents (already well-known to this 'XPN-centric crowd) melted our tablemates into fast friends.

Suddenly, bottles of magical 1989 Chateau Latour (current market value, $500 a bottle) were flowing freely from the Computer Mogul's stash at the other end of the table. The groups began to mingle. And the elaborate meal began to flow, slowly, but with some notable highlights.

Tellez and Boone, who took over Northbrook in the summer with their wives, pastry chef Leslie Tellez and catering director Christine Boone, come to this outpost outside Unionville with an impressive pedigree, including stints for both at Charlie Trotter's in Chicago (where Tellez was chef de cuisine) and, most recently, Striped Bass. Their food is gorgeously presented, inventively tuned to seasonal ingredients, and, though I had my quibbles, it was on the whole a fair nine-course bargain for $75 a person.

A starter of Indian chickpeas paired curried spice with the tender snap of hot-seared calamari. Silky mushroom soup pureed from local maitakes came topped with butter-poached bay scallops and oil-crisped celery leaves. A luscious cube of Chilean sea bass threaded with sweet red peppers was sided with earthy porcini mushrooms, crisp fingerlings, and a thick dollop of "hand-ladled cream," skimmed from the butter churn at nearby Down the Lane farm. A loin of local grass-fed Texas longhorn, lightly smoked in Northbrook's big smoker, was spectacular next to bacon-wilted brussels sprouts, caramelized parsnips, and heirloom tomato jam.

As intriguing as this food was, the two-man kitchen struggled to serve many of the courses as hot as they should have been to the big table. A promising terrine of wild mushrooms with lardons and a poached egg was also dimmed by grit left from careless mushroom cleaning.

It was also clear at my second dinner, when serving plates hot was not an issue, that the culinary concepts on these constantly changing menus are not equally fleshed out. A glass platter smeared with tangy pickled-beet puree topped with ribbons of deeply smoked salmon, shaved raw artichokes, snappy almonds, and bitter frisee lettuce was a masterpiece of contrasting textures and layered flavors. But a big ravioli filled with a chunk of sea bass, while an elegant idea, was too awkward to eat beneath the overly rich squash soup poured on top. A seared shrimp with spicy romesco sauce, likewise, needed something less creamy than the thick Alfredo-sauced angel hair pasta that came beneath.

Even Northbrook's busy smokehouse, so well used for the spectacular citrus-cured salmon and brisket, still needs fine-tuning. The applewood smoke didn't penetrate quite deeply enough into the ribs and tender pulled pork served in the cafe by day. The barbecue sauce, too, should be less gummy with thickeners. And the market's grocery aisles can still be significantly upgraded.

Without a doubt, Northbrook has a way to go before it competes on the lofty level of Talula's, with which comparisons are bound to be made. And yet, there is already so much to be excited about in this ambitious new venture. Whether pausing a bike ride for hot doughnuts, a brisket sandwich, and a fresh pumpkin whoopie pie or settling in for a sophisticated Chef's Table tasting, it's clearly a special addition to the West Chester scene - with the added element of spontaneous tablemates.

Our Friday meal, it turns out, took a surprise turn for the magical around midnight. As we spooned through Italian plum financiers and chocolate-pear bread puddings, Roy's vintage guitar suddenly appeared for an impromptu birthday serenade. And before we knew it, he and Gardot were treating us to a mini-concert. Strangers just a few hours earlier, this well-fed group had become an audience of new friends, totally rapt as the two voices bounded off the old planks of this 1850s barn, up and out into the starry West Chester night.