France ? The bacon is gone from the bacon burgers, replaced by smoked turkey. At a fast food restaurant outside Paris, a new certificate on the wall proclaims that its beef comes from cows slaughtered in line with Islamic law.

On Wednesday, popular French fast food chain Quick, the No. 2 burger chain in France after McDonald’s, started serving halal-only food in 22 of its French outlets, targeting France’s large Muslim population, an underexploited market that has long been ignored by big business.

If it’s a savvy business decision — Quick says sales doubled at restaurants that have tested the concept — the move has also opened a new chapter in the perennial war over how much society should accommodate Muslim traditions.