1) Chop Shop Casual Urban Eatery
4990 East Colfax Avenue
There's nothing terribly French about this East Colfax fast-casual stop, except for the sous vide cooking that results in a short rib that's impossibly tender yet still somehow cooked to a perfect medium-rare. Chef Clint Wangsnes uses the same method — vacuum sealing and cooking in a low-temperature water bath — to coax every last ounce of flavor from onions that are slowly caramelized over 72 hours. Wangsnes calls his creation Onion Bliss instead of simply French onion soup — and bliss it is, with a thick layer of bubbly Gruyere studded with herbs and the crostini on the side rather than wallowing in the broth. That broth, so loaded with umami that it almost burns, is rich and sweet and hot down to the last spoonful in its little cast-iron pot. At just $5.50 for the big portion, the Onion Bliss is a miniature masterpiece of intensity.
2) ChoLon Modern Asian Bistro
1555 Blake Street
There's nothing secret about ChoLon's diminutive steamer basket filled with French onion soup dumplings; chef/owner Lon Symensma's French ode to Chinese xiaolong bao is one of the most celebrated dishes in Denver. That doesn't make the dumplings any less beckoning as a cool-weather treat — or any less astounding every time we slurp up the jiggly spheres. The trick to making these soup dumplings is that the oniony broth is cooked down and enriched to the point that it's a gelatin when chilled, allowing it to be scooped onto circles of dough — along with pungent Gruyere — before they're sealed up with pinched pleats. A few minutes of steam liquefies the soup inside the delicate pouches so that they burst on your tongue in a cascade of savory sweetness.
1076 Ogden Street
Barricuda's isn't exactly a dive; now 22 years old, it's more of a neighborhood bar and late-night diner with reasonably priced food. Still, the dated decor and dim lighting skews more divey than today's trendy eateries clad in beetle-kill pine and peddling Colorado craft ale and artisanal spirits. But if you're looking for a friendly and unpretentious hangout to drink away the hours, or just a fast, filling lunch, Barricuda's is a winner. The kitchen makes its own French onion soup and serves it in little stoneware pots slathered in molten Swiss, exactly the way every diner in America has done the dish since it was popularized in the 1960s. After tilting back the bowl to down the last sips of the mild broth, you can peel brittle bits of cheese from the rim as a bar snack to go with your whiskey Coke. Classy.
4) Cafe Marmotte
290 South Downing Street
The new Cafe Marmotte is pure French at heart, with coq au vin and foie gras coming from the kitchen in their purest forms. But chef Mark Reggiannini isn't afraid to stray from the formula — and his onion soup is a case in point. Rather than a mahogany broth laced with slow-cooked onions, this version is pureed with cream to bring out the pure essence of the onion. Despite the dairy, the soup is light and airy — and it's also made without meat, so a vegetable stock does the work of building a foundation of flavor. And, yes, there's Gruyere, but it's tempura-fried and placed like a tiny life raft in the center of the bowl. This is an unusual interpretation of a classic, but one that fits nicely atop Marmotte's four-seater bar sided by a glass from the excellent wine list. Bon appetit!