It was a standing-room-only crowd at the Modern Cafe on Saturday night, a day after owners Jim and Patty Grell announced plans to sell their 20-year-old restaurant.

You'd think the couple would have been working the dining room, soaking up the love from the well-wishers thronging the northeast Minneapolis landmark.

But, no. They were downstairs, in the restaurant's dreary basement prep kitchen; he was trimming vegetables, she was up to her elbows in industrial-strength rubber gloves, scrubbing pots.

Yes, the glamorous life of restaurant ownership. After two backbreaking decades, the couple have had their fill.

"The restaurant is 20, and I just turned 50, and I'm old, and I'm tired," said Jim Grell, who got his start in the business at the former Giorgio's and D'Amico Cucina, both in Minneapolis. "We're not failing. I just don't want to be doing this when I'm 60."

The buyer's identity remains a mystery. Ditto the intentions for the 74-year-old building.

"They're going to make their own announcement," Jim Grell said.

The Grells debuted their modern-day diner on Aug. 8, 1994, in the former Rabatin's Cafe, focusing on contemporary renditions of blue-plate fare.

The Modern's innovative formula, a savvy blend of scruffy nostalgia, expert but unpretentious cooking, engaging service and value-conscious prices, was an instant hit, luring folks from the neighborhood, as well as food-loving adventure-seekers from across the metro area.

At the time, the menu's top price was $6.50 for a pan-roasted chicken breast with garlic mashed potatoes. Meatloaf was $6.25, and the dish that would come to define the restaurant, pot roast, weighed in at $6 (it's now twice that price at lunch, and three times as much at dinner).

Oh, that pot roast, which has long enjoyed its status as one of the region's most enduring signature dishes. Refinements have only improved it, but at its essence it has always remained a fist-sized hunk of succulent, lovingly braised beef, served with onion-steeped pan juices, carrots caramelized to dessert-level sweetness and mashed potatoes infused with enough butter and cream to support a small dairy farm.

Over the years, there were times when a better pork chop — or a more impressively stick-to-your-ribs plate of green-onion biscuits smothered in sausage-studded gravy — could not be found outside the Modern's doors. Heck, even the pickles approached hall-of-fame status.

But I suspect that, when the history books are written, it's the pot roast that will be exalted, a dish as fabled as the potato salad at the long-gone Charlie's Cafe Exceptionale.

I can barely remember a Twin Cities dining scene without the Modern, and the restaurant's long run is a towering achievement. After all, in the twisted mathematics of the industry, 20 years is the equivalent of a century. That longevity is even more impressive considering the restaurant's low-budget roots.

"We were just laughing about how, when we opened, we didn't have a phone, because we couldn't afford it," Jim Grell said. "We had a pay phone, and I used to take quarters out of the register when I had to make a call. I got a quarter, called [former Star Tribune restaurant critic] Jeremy Iggers and said, 'Hey, I just opened a restaurant, and we want you to write about it.' "

Over the intervening years, the Modern not only made comfort food hip, but the restaurant forged a defining role in the local move toward casual neighborhood dining. The throwback decor, a novelty in 1994, grew into a design standard.

Another innovation: Fifteen years ago, the Grells quietly introduced the much-copycatted half-price wine craze.

The restaurant's popularity also proved to be a catalyst in the neighborhood's revival. It's impossible to imagine today's thriving Northeast minus the Modern's paving-the-way role.

And the personality-driven restaurants of today? Their lineage can be traced directly to the Modern's playful snarkiness. Somewhere I've got one of Jim Grell's business cards (I should donate it to the Minnesota Historical Society), and instead of "chef" or "restaurateur," it reads "rocket scientist." I'll never forget how much fun it was to dine at the Modern.

Talent incubator

The Modern's impossibly tiny kitchen has been home to several influential Twin Cities chefs, including Mike Phillips (now the owner of the nearby Red Table Meat Co.), Scott Pampuch (former chef/owner of Corner Table in south Minneapolis, now at the University of Minnesota) and Phillip Becht (now at Victor's on Water in Excelsior).

Chef Ella Wesenberg currently runs the show, and under her tenure, the kitchen's output has remained as compelling as the day the doors opened.

Back to last Saturday night. At one point in the evening, when it appeared as if the addition of another diner in the standing-room-only room would trigger a finger-wagging visit from the fire marshal, Jim Grell emerged from the kitchen door, with Wesenberg in tow.

"Can I have your attention, please?" he shouted over the din. The place fell silent. He grabbed Wesenberg's hand and raised it over her head.

"A woman is cooking your dinner," he said, and the crowd erupted in an ovation worthy of the state high school hockey tournament.

Saying goodbye

The restaurant, which will remain in the Grells' hands through March 14, has quietly been on the market for several months. Asked about his post-sale plans, Jim Grell, ever the quote machine, deflected, only to say he's leaving the restaurant business. And then he tossed off a typical Grell-ish response.

"I've been in contact with Jon Stewart and Lucia Watson, and we're forming a band," he said, referring to the soon-to-depart host of Comedy Central's "The Daily Show" and the founder of Lucia's Restaurant, who sold her 30-year establishment in the Uptown area of Minneapolis in December. What will he do in the band?

"Whatever Lucia tells me to do," he said. "She's my hero."

Mine, too. In all honesty, I can't call myself a true Modern regular, although I wish I could. I'll leave that proud distinction to a trio of my acquaintance who have been enjoying lunch at the House of Grell on a close-to-four-times-per-week schedule for more years than I can recall.

Still, I have turned to Modernism probably four or five times each year over the course of the past two decades. What is that, maybe 100 meals? In retrospect, I wish it had been 200.

Goodbye, old friend. You'll be missed.

Follow Rick Nelson on Twitter: @RickNelsonStrib