The sushi chef's monopoly on eel ends when burger flippers at Shake Shack start cooking their own limited-time catch. 

We thought Shake Shack had hit peak fanciness when it served fresh Maine lobster piled on top of its beef burgers for one weekend in August, but Danny Meyer's cult-favorite burger chain has proved us wrong: It's grilling up eel burgers this Saturday and Sunday.

On Sept. 15 and 16, Shake Shack is collaborating with Michelin-starred British chef Fergus Henderson to serve a $9.99 burger made with smoked eel at its original location in Madison Square Park. The sandwich comes with smoked bacon for some extra umami, pickled red onion, crème fraiche, fresh horseradish for some bite and the Brit's preferred greens, watercress, on top. 

Henderson's restaurant — named among the world's 100 best restaurants in 2017 — will also trot out its signature vanilla custard-filled doughnuts ($3.99) and bespoke red ($8.99 for a six ounce serving) and white wines ($7.99), which the eatery apparently produces at its very own medieval winery in southwest France.

It's all très chic to us.