For example, Boston Chicken sells a lot of squash in the South and baked beans in the Northeast. But its biggest-selling side dish nationwide is mashed potatoes. And its seasonal fruit salads change from region to region.
Increasingly, having it your way means more that just a choice of condiments or degree of cooking. More chains are gearing their menus to regional, even neighborhood tastes. In 1992, KFC introduced African American menus in urban areas such as Philadelphia, Baltimore and Detroit.
Now more than 300 KFC urban outlets nationally offer hotter, spicier chicken and several soul-food side dishes, including Mean Greens (collard and turnip greens seasoned with smoked ham), red beans and rice, sweet potato pie and peach cobbler.
Fast-food chains such as McDonald's, Wendy's and Burger King, as well as more upscale chains such as the Olive Garden restaurants, give the same attention to regional tastes.
"Our Hot 'n Spicy chicken sells very well," said Denise Brown, KFC manager at Broad and Bainbridge Streets. She estimates the sales split for that location at roughly 60 percent Original Recipe, 30 percent Hot 'n Spicy and 10 percent Rotisserie Gold.
"But I have days when customers want mostly rotisserie chicken, and others when most want spicy chicken. We have a mixed clientele here. Customers who live in the area and come in almost daily buy all of it.
"New customers and visitors in the area or tourists usually try the rotisserie chicken."
The African American menus have been "a huge success," Litterst said, but similar options for Hispanic areas (fried plantain, black beans and rice, etc.) were abandoned when patrons in the Miami test markets made it clear that that particular group would rather do its own ethnic cooking.
Because fast-food and family restaurant chains trade on consistency, on their customers' trust in being served the same familiar food whenever or wherever they visit, recipes typically remain firm nationwide.
Big Macs, for instance, are the same from Paris, France, to Paris, Texas.
At most chains, the selection of optional menu items gives the measure of local tastes.
Regional specialties, said McDonald's spokeswoman Jane Hulbert, more often are found in limited areas and on a seasonal basis.
"Like in New England, we'll do a McLobster Sandwich; and in Maryland, a McCrab sandwich," Hulbert said.
"The breakfast burrito originated in the Southwest. In Chicago, it's a popular optional item."
Just how popular such items may be is unclear, since all the chains we talked with consider sales information proprietary and spoke only in general terms.
Burger King, for instance, is stressing a back-to-basics approach, offering some variety but recognizing that customers come to Burger King for burgers.
Along with the flagship burgers carried at all locations, there are optional items, such as breakfast burritos, BLT cheeseburgers, and popcorn, said spokeswoman Kim Miller.
"Some markets in the Northeast and Mid-Atlantic area have the hamburger minus mustard," she noted. "In the Southwest, they have picante sauce and diced green chilies. And we have kosher food in Israel."
But overall, said Miller, Burger King found that too many choices made operations unwieldy and inefficient.
At Wendy's, spokesman Denny Lynch, sees a greater blending of tastes over the last 20 years, with more regional foods offered nationwide.
"Years ago a breakfast sandwich had to be on an English muffin in New England and on a biscuit in the South," Lynch said. "Now bagels have found their way into the (fast food) market. And you can find biscuits in New England and muffins in the South."
Burger King offers bagel breakfast sandwiches. McDonald's has them with cream cheese. Bagels are so widespread that, though once rarely found outside New York, they've become almost white-bread. Californians are eating jalapeno bagels and chocolate chip bagels. And Jimmy Dean, prototype country boy and sausage king, has added bagel sandwiches to his prepared food line.
Philadelphia's tastes - unlike California's - lean to the traditional.
"You like onions more in your part of the country," Lynch noted. "But Wendy's (in Philadelphia) sells about the same amount of hamburgers, chicken and salads (proportionally) as our national average.
"We try to have a homogeneous menu nationwide, but some stores offer special items occasionally. For instance, a Philly cheeseburger with sauteed onions and cheese sauce has been available from time to time in (Philadelphia).
"Right now, in the Carolinas, we're testing a Carolina cheeseburger topped with a little bit of chili and coleslaw. It's an unusual combination, but in Carolina, they seem to love it.
"In Upstate New York, there's a Buffalo-wing-style chicken sandwich on a hamburger roll with blue cheese and bacon. And in Texas, the special item is two small cheeseburgers stacked with extra mustard, pickle and onion. It's very popular, and has spilled over into the Southwest."
But make sure that's yellow mustard, pardner.
"You would not find Grey Poupon on a Texas burger," Lynch said.
Limited-time-only regional additions to Wendy's basic national menu are a chance to try new recipes and pique consumer interest, Lynch said. One such offering being promoted nationally later this month, he added, is Wendy's Chicken Cordon Bleu sandwich with ham, Swiss cheese and, yes, Grey Poupon.