Bley, visiting from Los Angeles and sitting with her son, speaks excitedly.
"I've been waiting three weeks for this," she says, as a waiter wearing a red tie and blue striped apron presents the forbidden pate on a wooden plank. She smears some of the foie gras on bread and takes a bite.
"Fabulous," she pronounces. "Absolutely fabulous. It's creamy, it's lovely. It's liver so of course it's very good for you."
Since the ban went into effect July 1, hundreds of people have continued to enjoy foie gras.
Presidio Social Club management contends the law doesn't apply to them because the restaurant is on federal land owned by the National Park Service. And across the state, other restaurateurs and chefs are using loopholes and clever wordplay to keep the dish on the market, a sign that passions run high on both sides of the issue.
Animal rights' activists, meanwhile, say foie gras is the product of cruelty: ducks or geese are force-fed with funnel-like tubes until their livers become engorged. California's ban makes it illegal to sell food derived from force-fed birds.
Bley is not impressed by the state's reasoning.
"I'd never think of telling a vegetarian not to eat a carrot yanked from the ground with its friends the worms around it," she says.
Chefs at Hot's Kitchen in Los Angeles County and Chez TJ restaurant in Mountain View, Calif., are serving foie gras as free side dishes, arguing that the ban does not explicitly prohibit distribution.
Other establishments, like San Francisco's Palio d'Asti, are offering to have their chefs prepare any foie gras brought in by customers. Bley says she's stockpiled livers in her freezer that a restaurant in Los Angeles cooks for her.
Rob Black, the executive director of the Golden Gate Restaurant Association, said these actions reflect how the law created an "environment where you don't know what's legal. It creates confusion what restaurants or distributers can or can't do."
The attempts to get around the ban have angered the man who introduced it in 2004, former state Sen. John Burton.
"Shame on them, it's the law," Burton said.
Animal control officers have investigated one restaurant in San Francisco and plan to investigate another for selling foie gras. An agency representative said the restaurants exploiting the law have put enforcement in a bind.
"I think the law has some major loopholes, and we cannot extend the law," said Animal Care and Control Deputy Director Kat Brown.
Elsewhere in the state, responsibility for enforcement is unclear. In Los Angeles County, the Department of Public Health plans to investigate restaurants that sell foie gras as part of its health inspections unless told otherwise, representative Angelo Bellomo said.
But other agencies that could potentially fine offenders do not have the means to do so.
"With budget cuts, this just isn't something we can add to our plate right now," said Marcia Mayeda, director of Los Angeles County's Department of Animal Care and Control.
Legal experts said the Presidio Social Club might be on safe legal ground in defying the ban because courts have held that state regulations generally do not apply to federal property. They do not hold sway on Native American reservations, either.
But some business owners said they will follow the law even if they may not have to, including restaurants in Yosemite National Park. Some California casinos on Native American lands also removed foie gras from their menus.
"We felt like the general public's desire to have (foie gras) eliminated from menus in California was more significant than keeping it on the menu," Thunder Valley Casino spokesman Doug Elmets said.