I have a newfound fascination with oysters. My obsession with these mysterious mollusks got kicked into high gear when a friend threw a dinner party featuring roasted oysters. The farmed Long Island Blue Points, purchased that morning at the fish market, were served hot in large bowls and we were given oyster knives to pry them open. It was a messy job, with the juice spilling in unintended places (my neighbor's pant leg, for instance), but the hard work of shucking made the oysters even more enjoyable. Accompanied by a simple mignonette sauce and a glass of rosÃ, they tasted darn near perfect.

Even before the party, oysters were on my radar. They captured my attention when I decided to boost my iron intake through dietary changes. With a little research, I discovered that oysters are high in iron, so it gave me a good excuse to indulge in this "luxury" food. I'd always liked oysters, and knowing they were good for me only increased their appeal.

But health wasn't my only attraction to this prized bivalve. While writing my cookbook, I spent a lot of time learning which fish and seafood are caught or farmed sustainably, and I found that oysters - along with mussels, clams, and scallops - can actually help to improve the quality of coastal waters where they are farmed. Oysters feed by filtering tiny plankton out of the water, so they do not need to be fed with wild-caught fish (in the form of fish oil or fishmeal) as do most farmed fish. They are generally not susceptible to disease, so there is no need to feed them antibiotics, and they are unlikely to escape and contaminate wild populations with disease - both common problems with aquaculture.

Finally, oysters are grown suspended in water, which means that when they're harvested there is no need to dredge the sea floor, a widely used fishing technique that is a major cause of habitat destruction. Both the Environmental Defense Fund and the Monterey Bay Aquarium place farmed oysters on their list of most highly recommended seafood choices.

Luckily for me, oysters are a common feature of many Manhattan restaurant menus these days, and it's not just seafood joints. Oysters are a mainstay on the gourmet landscape because farming has made them available all-year-round. There is an old saying that one should only eat oysters in "R" months, that is, every month except May, June, July or August. The saying was based on changes in the marine environment that made the oysters more prone to carrying bacteria in warm weather. Now that oysters are grown in carefully monitored farming operations, we can safely enjoy them throughout the year.

But back to my friend's dinner: Because the guests did the shucking, the oysters were quite affordable - about 25 cents each. I love this idea for a party. Have guests do the work, or hire someone just to take care of this task. I don't know about you, but give me some good oysters, wine, and salad, and throw in some carbs (fresh bread will do perfectly) and I'm very well satisfied. I say, keep the menu simple and keep the spotlight on the oysters. I recommend including oysters at your next special gathering, either roasted or raw, shucked or unshucked, but definitely farmed and definitely fresh.

Recipe: Oven-Roasted Oysters from The New York Times, March 16, 2005

Time: 45 minutes

100 to 120 unshucked oysters, scrubbed clean

6 small lemons, cut into wedges

Tabasco, or other pepper sauce

Sour orange mignonette

1. Heat oven to 475 degrees. Working in batches, arrange oysters in a single layer in a 12-by-16-inch roasting pan fitted with a flat rack. Pour 1/3 inch of hot tap water into pan, and bake for 7 minutes, or until oyster shells have begun to open.

2. Using gloves or tongs, transfer oysters to a table covered in newspaper for guests to shuck, garnish and eat while next batch cooks. Add water to pan as necessary, and repeat roasting until all oysters have been served, about 45 minutes. Serve with lemon wedges hot sauce, and sour orange mignonette.

Yield: 8 servings.

Written By Louisa Shafia, Author Of Lucid Food: Cooking for an Eco-Conscious Life (Ten Speed Press)

After working as an editor on NPR's Fresh Air, then pursuing an acting career that peaked with a low-budget horror film, Louisa took a job cooking at a yoga retreat. The guests loved the food, and she loved the work, so she went to cooking school. In 2004, she brought her unique take on earth-friendly food to the world of fine catering with the Lucid Food consultancy, specializing in seasonal and local food and low-waste events where supplies are recycled or composted.