The Dish: mango and key lime mousse

The Location: Thunder Grill, Union Station, 50 Massachusetts Ave. NE, (202) 898-0051

The Price: $4.50

The Skinny: Purists may insist that mousses oughta be chocolate and key limes belong in pies. But one entry on the dessert menu at Union Station’s Thunder Grill—a mousse made of mangos and key-lime juice—adds up to a relatively unique desert: Though “chocolate mousse” and “key lime pie” notch roughly 1.5 million and 1.03 million Google hits, respectively, “mango mousse” dishes up only 66,600, “key lime mousse” stalls out at just 955, and “mango and key lime mousse” and “key lime and mango mousse” get one apiece. But once it’s on the palate, Thunder Grill’s bright-yellow concoction (which comes topped with cookies and fresh berries) ceases to be threatening or even particularly revolutionary. It’s simply a pleasantly tart after-dinner treat. Diners may be more likely to gravitate towards cheesecake, pecan pie, and other traditional entries on the restaurant’s dessert menu, Thunder Grill manager Gregg Thompson says, “but because we are in a train station, where you have people traveling from everywhere, you always have that adventurous person that will try it.”