It's a fair bet that the gambling earl wasn't the first to construct a sandwich, despite his name being indelibly wedded to the concept (before his time referred to simply as "bread and meat"). Medieval feasters were served meat on trenchers (large slices of stale bread) instead of plates. The meat juices would soak into the bread, which would then be eaten, given to the poor, or thrown tot he dogs that lurked beneath the banqueting tables. The basic idea of filing between two layers of pastry or dough, found in many cuisines in the form of tortas, pasties and pies, is really just the sandwich in a slightly different form.

The infinite adaptability of the sandwich continues to be toyed with today, in a wealth of appetizing and original combinations of artisan breads and wraps, unusual filings and new condiments appearing on menus in QSR's, sandwich outlets and even high-end eateries run by top chefs. Ciabatta, a specialty Italian bread virtually unknown in the US just a few years ago, is now featured in a line of premium chicken sandwiches at Jack in the Box, enabling the popular chain to offer upscale ingredients at an affordable price. Chains dedicated specifically to sandwiches, like Panera Bread, Atlanta Bread Company and Quiznos Sub, are rolling out carefully crafted combinations of filling, bread and condiments, such as roasted chicken and smoked Gouda cheese with pesto aioli on sesame semolina bread (Panera), Cuban pork loin with spicy mustard and roasted pickled onions on grilled foccacia (Atlanta Bread Company) and Black Angus steak with mushrooms and sauteed onions on rosemary Parmesan bread (Quiznos).

The "high-concept" sandwich is turning up on the menus of some of the top chef-driven restaurants. "Grilled cheese nights" at Campanile restaurant in Los Angeles have become wildly popular, with 14 variations on the all-American favorite including versions featuring roasted asparagus, poached egg and fontina with prosciutto, and Welsh rarebit, roasted cherry tomatoes and charred baby broccoli with chili oil. Tom Colicchio, chef of NYC's highly regarded Craft restaurant, recently opened a spin-off christened wichcraft, serving sandwiches made with top quality ingredients. Among the offerings are the classic PB & J in a tripe-decker version on Pullman loaf, and a Mediterranean-inspired Sicilian tuna, fennel, black olive and lemon combo on a baguette.

Surely the most seriously up-scaled sandwich of late has been the hamburger. It took French chef, Daniel Boulud, to start the ball rolling with a burger made of ground sirloin filled with braised short ribs, foie gras and black truffles on a homemade bun, with a hefty price of 29 dollars, Since then, top chefs have been vying with one another to create high-end burgers with ever higher price tags, culminating in the opening of the Burger Bar at Las Vegas' Mandalay Place. Not your typical hamburger joint, the Burger Bas is a build-your-own burger concept where customers choose from meats like Kobe, Black Angus or Ridgefield Farm beef and toppings including prosciutto, black truffles, portobello mushrooms and grilled peppers, onions and zucchini. Sixty dollars buys you a Rossini burger with Kobe beef, foie gras, truffles and Madeira sauce on an onion bun.

Lest you should think the sandwich is a purely American phenomenon, check out some of the hot ethnic-inspired versions now popping up on menus across the country. Enterprising immigrants have always found their way into the foodservice industry, often opening small take-out shops and restaurants featuring the specialties of their homelands. Banh mi is the Vietnamese take on the submarine sandwich, with various combinations of ham, pork and pate layered on a baguette (a legacy of the French occupation of Vietnam) and sparked with picked vegetables, cilantro and chiles. Banh mi shops have long been a staple in cities with significant Vietnamese populations, but lately the sandwich has been popping up on non-ethnic menus as well-Pangaea, a "global sandwich concept" in Atlanta, even has a separate category for banh mi on its menu.

The Cubano sandwich, a favorite late-night snack on its island of origin, was a natural crossover, with layers of ham, roast pork, Swiss cheese and pickles grilled to meltingly warm perfection in a sandwich press. New York City's 5 Ninth does an upscale version with organic pork and prosciutto on an artisan baguette, and Acme Chophouse at San Francisco's SBC Park features the Cubano on its bar menu.

The Middle Eastern influence shows up in shawarma, a pita sandwich stuffed with grilled chicken, tomatoes and a garlicky sauce, and the ever popular Greek gyros-ground lamb grilled on a rotating spit, then piled in a pita with cucumber yogurt sauce, onions and tomatoes. The growing influence of Mediterranean cuisine beyond Italian, French and Spanish has given these sandwich variants fresh appeal.

Whatever the price or inspiration, all but the most basic sandwiches are a combination of bread, filing, and condiment or garnish. From QSRs on up, operators are using specialty breads like focaccia, ciabatta, and breads incorporating cheese, nuts and herbs. Chains like Panera and the Corner Bakery tout their in-house bakeries, while smaller operations feature artisan breads from local suppliers. Tortilla wraps in colorful tomato and herb versions offer a twist on hand-held sandwiches, as do ethnic flatbreads like Indian naan, and Middle Eastern pita bread or lavash (an Armenian cracker bread that's soaked, then layered with cream cheese and other fillings and rolled up like a jelly roll to make the popular aram sandwich).

Meat and cheese are perennial favorites as sandwich fillers, with the emphasis shifting from sheer quantity of ingredients to quality and intriguing new combinations. Cheese is no longer limited to Swiss, cheddar or provolone, but now includes Gouda, bleu cheese and, following the bread trend, artisan cheeses.

With the trend towards healthier eating, the proportion of vegetables in sandwich fillings has grown; in fact, all-vegetable sandwiches have carved out quite a niche of their own. The rich, caramelized flavor of roasted or grilled vegetables is assertive enough to stand alone or to complement meat or cheese. Simplot's RoastWorks line of flame-roasted vegetables includes the ever-popular peppers and onions, perfect on subs and burgers, as well as a flame-roasted Mediterranean blend to help inspire flights of creative fancy. Paired with specialty breads, meats and cheeses, and creative condiments like pesto, flavored aioli and mustard spiked with horseradish or herbs, RoastWorks vegetables are a great way to build a more up-scale sandwich without a lot of prep.

Think avocados when you want to add flavor and flair to Latin-themed sandwiches like the Cubano or increase the value and appeal of those perennial favorites, the BLT and the club sandwich. Simplot's wide range of quick-frozen avocado products makes it easy to find the most convenient type, whether you need slices for a sub or guacamole for a wrap, with year-round consistency in ripeness and cost.

Don't forget the importance of "sides" when designing a sandwich plate. The Cubano pairs up nicely with a zesty salsa made with RoastWoks flame-roasted corn and black bean fiesta blend. And warm sandwiches, whether a burger or a deep-fried Monte Cristo, up-size from a snack to a meal when served with a potato side like RoastWorks Yukon gold wedges or mesquite roasted redskin wedges.

The sandwich has come a long way from the earl's makeshift meal, as chefs in all sectors of foodservice continue to innovate with new ingredients, ethnic influences and flavor combinations, while putting a new spin on the old stand-bys.