Frankly, the sight of whole geoduck (pronounced "gooey-duck," from the local American Indian term for "dig deep") can be off-putting. At its most extreme, the mollusk can weigh more than 15 pounds, its wrinkled gray siphon protruding as much as six feet from its oblong shell. Specimens are strikingly phallic, which may explain why geoduck is considered an aphrodisiac in many Asian cultures. Though on the other side of the Pacific it has long been revered as a delicacy, in the American Northwest, where the bivalve is native, geoduck has only recently started showing up on menus, primarily at locavore restaurants. I ate the tender, edible siphon in a ceviche with serrano chiles and green mango at Xinh's Clam and Oyster House in Shelton, Washington, and flash-sauteed with ginger, citrus, and fermented black beans at Matt's in the Pike Place Market. Matt's chef, Chester Gerl, even told me he'd wooed his wife with a plate of smoked geoduck. If this giant clam can lead to love, I thought, I'd better learn how to cook it too.