Oysters, mussels, and clams are "an excellent choice because they are farmed in an environmentally responsible way." Prefer local farmed shellfish, because shellfish should be purchased alive and extremely fresh. Ours come from Hog Island, an environmentally-careful shellfish farm in Tomales Bay. They primarily trade in oysters, and at Farmers' Market one can buy fish to take home and also oysters on the half shell to eat right there. Mmmm good.
Expect a pound of mussels and a pound of dried pasta to satisfy two people. Prepare the pasta very light: we had farfale, tossed with sage-butter.
In a large pot, combine two cups vegetable broth, two cups of white cooking wine, a few stocks of green onions, cleaned and diced, half a dozen whole garlic cloves, and a fair amount of salt. Add the mussels, and enough water to cover, and bring gently to a boil.
The mussels are done when the water boils, but there's no harm in letting them sit a little while. The mussels should open up in the water. Do not cook any mussels that are open when dry — those are dead and may make you sick — and similarly discard any mussels that do not open when cooking. With a slotted spoon, remove cooked mussels to a large ceramic bowl, and pour over as much broth as will fit without spilling. Present the mussels in the bowl with broth, and serve at the table with the slotted spoon.
Save the shells for a fish stock, of course, which should be prepared with shellfish (crab, lobster, clam, oyster, etc.) shells, fish bones, and fennel, leeks, and onions. Since I don't really have the space or time to keep different bags of stock scraps, these mussel shells went in the vegetable-broth bag with the beets and carrots and garlic.