When Christophe Happillon comes to your table at Saint Amour or Joe's to discuss a "dry, lemongrass finish," he's not talking about wine--he's talking about oysters. Like a good sommelier, this maitre écailler--or seafood specialist--brings a more intimate approach to eating bivalves.

Not only does he personally shuck and serve the oysters from his roving cart (at Saint Amour on Thursdays, and Joe's on Fridays), he'll also wax poetic about their characteristics.

He can tell by the size and smoothness of the outer shell whether the oysters are from the North Atlantic or the Pacific. Then he'll cover what's inside: The meat's texture could be soft, crunchy or chewy; the liquid could be dry or milky; and the finish could have citrus or melon notes. It all comes from the meroir--like terroir for wine.

"Oysters are like sponges," he says. "They concentrate all the flavors of their environment."

Although he serves shellfish from all over North America, he does have some favorites:

Carlsbad Luna From SoCal's Carlsbad Aqua Farm, these plump, high-acid oysters have a grassy, metallic finish.

Totten Virginica These are firm and smooth oysters with a fruity, buttery taste.

Kumamoto Tiny and plump, these West Coast oysters are a bit crunchy in texture and have a balanced melon flavor.

Malpeque These Prince Edward Island oysters are briny and creamy.