Meet the latest burger. It has cast away the layers of condiments, the mountain of add-ons that turned the basic burger into a tower of toppings. Burgers have a new mantra: Stop piling it on and start mixing it in.

Instead of putting cheese, bacon and mushrooms -- and let's not forget all the sauces -- on top, burgers now are getting seasoned from the inside out. The bacon cheddar burger is a melt-in-your-mouth combination of ground beef, grated cheese, diced smoky bacon and golden onions, perfectly proportioned and mixed together. Other pairings might include a Swiss-mushroom burger that bypasses the bacon altogether or a spicy jalapeno-laced turkey burger.

"People were getting tired of the plain old hamburger," explains Theo Weening, meat coordinator for Whole Foods Markets. So last year, Whole Foods rolled out a line of burgers ranging from the bacon and blue to veal Florentine with the flavors stuffed inside.

When Balducci's started polling customers about what they wanted to see in the meat counters, burgers topped the list, according to Kevin McDade, the retailer's meat and poultry merchant. The decision to introduce the seasoned, ready-to-cook burgers in the stores this summer was based on customer feedback. "We tested the burgers in the Bethesda store and got a good response, so we brought in a bunch of flavors," McDade says.

The store-bought burgers offer convenience, but there's no reason not to create them in your own kitchens. Anybody looking for a lot of flavor without too much fuss can easily whip up these burgers at home. The add-ons are diced, sometimes cooked and then mixed right into the ground meat of choice. In fact, you can mix in many of the ingredients you probably had ready to pile on top of the burger. The whole process takes only a few minutes. Even when the ingredients are cooked before being added to the meat, the burgers can be thrown together in less than 15 minutes.

Stephanie Witt Sedgwick, a graduate of the Culinary Institute of America, likes to grind her own meat for burgers.