Californians will be able to legally eat foie gras again after a judge Wednesday overturned a ban on sales of the delicacy, outlawed in the US state for the past 18 months.

One restaurateur who has fought the ban said he would begin serving foie gras again immediately.

“It will be back on the menu tomorrow,” said Sean Chaney, chef-owner of Hot’s Kitchen in Hermosa Beach, adding: “It’s awesome… what a way to start the new year.”

Opponents of foie gras, produced by force-feeding geese or ducks, slammed the ruling by a federal court.

“Foie gras is French for fat liver. And fathead is the American word for the shameless chefs” who serve the gourmet food, said animal rights protection group PETA.

“A line will be drawn in the sand outside any restaurant that goes back to serving this torture in a tin,” it added in a statement.

California lawmakers agreed the ban in 2004, but gave the western US state’s foie gras producers seven-and-a-half-years to comply before it came into effect on July 1, 2012.

Restaurants serving the dish can be fined up to $1,000.

The ban has for the last 18 months outlawed force-feeding ducks or geese to make foie gras within California and bars sales of foie gras produced elsewhere if made by force-feeding a bird to enlarge its liver beyond normal size.

In his ruling Wednesday, US District Judge Stephen Wilson wrote that the law was unconstitutional because it interferes with an existing federal law regulating poultry products.

The foie gras ban was “a topic impacting gourmands’ stomachs and animal activists’ hearts,” the judge wrote.

The ruling came after an association of producers who supply Canada’s foie gras imports to the United States and Hudson Valley Foie Gras, the largest US producer, sued in Los Angeles to overturn the law.

Lawyer Michael Tenenbaum, who filed the civil suit against the state of California, said his clients alone are losing at least $15,000 per day as a result of the law.

California Attorney General Kamala Harris’s office said it was reviewing the ruling, but had no immediate comment.

The Animal Legal Defense Fund and the Humane Society vowed to appeal the ruling.

“The state clearly has the right to ban the sale of the products of animal cruelty… We are asking the California Attorney General to file an immediate appeal,” they said in a joint statement.

In the run-up to the 2012 ban, some of the Golden State’s top chefs, calling themselves the Coalition for Humane and Ethical Farming Standards (CHEFS), redoubled efforts to persuade lawmakers to overturn the ban.

They staged a series of foie gras-rich evenings to raise money for the cause. But John Burton, the former lawmaker who drafted the legislation, likened foie gras production to outlawed practices such as waterboarding or female genital mutilation.

“I’d like to sit all 100 of them down and have duck and goose fat — better yet, dry oatmeal — shoved down their throats over and over and over again,” he told the San Francisco Chronicle.