HERE'S THE CONCEIT: Build a single wood fire and, over the course of 30-plus hours, use it to roast, braise, bake, simmer and grill as many different dishes as possible -- for lunch, dinner, breakfast and lunch again. The main ingredients: one whole goat from the McCormack Ranch in Rio Vista, Calif.; several crates of seasonal produce (and a case of olive oil) from Hudson Ranch in Napa; a basket of morels and porcini gathered near Mount Shasta; an assortment of spices from Boulettes Larder in San Francisco; and a couple of cases of wine from Kermit Lynch in Berkeley. The setting: a shady backyard in Napa (but picture suburban subdivision, not vineyard estate), where a big country table stretches out beneath the canopy of a mulberry tree. The cast: three accomplished Bay Area chefs (Mike and Jenny Emanuel -- whose kitchen and backyard we've commandeered for the weekend -- and Melissa Fernandez), one gifted baker (Chad Robertson), one jack of all culinary trades (Anthony Tassinello) and two amateurs (me and my 17-year-old son, Isaac). The guests: all of the above, plus a rotating crew of spouses, children, friends and neighbors. The fire: almond, oak and mulberry logs burning in a cob oven that Mike Emanuel built with the help of some friends in 2006. A cob, or earth, oven is a primitive, domed cooking device that can be made from layers of mud, clay, straw, stucco, even manure; the earthy mixture, the cob, can endure much higher heat, and hold it much longer, than an indoor oven can. Emanuel's incarnation, which he built ''to bring together family and friends for extended feasts,'' stands 5 feet tall with a 30-inch hearth and looks like a cartoon character: a visitor from a planet of chubby, eyeless, big-mouthed monsters. The inspiration for this pyro-gastronomical experiment was the communal ovens still found burning in some towns around the Mediterranean, centers of social gravity where, each morning, people bring their proofed, or risen, loaves to be baked. (Each loaf bears a signature slash so you can be sure the one you get back is your own.) But after the bread is out of the oven, people show up with a variety of other dishes to wring every last B.T.U. from the day's fire: pizzas while the oven is still blazing and then, as the day goes on, gentle braises or even pots of yogurt to capture the last heat and flavors of the dying embers. [ABSTRACT FROM AUTHOR]