When you're in the mood for something out of the ordinary at lunchtime, these unique sandwiches will hit the spot. Try a tuna sandwich inspired by Nicoise salad, a Vietnamese-style sloppy joe, a muffuletta, Italian braised pork with caramelized apples, or a luxurious lobster roll.

The ingredients of a Nicoise salad -- oil-packed tuna, cucumber, red onion, hard-cooked eggs, and olive tapenade -- combine in a lunchbag-perfect sandwich. For the best flavor, make the sandwich at least an hour ahead of time.

These Vietnamese-style sloppy joes combine ground beef with shallot, lemongrass, and red curry paste in a ketchup and Dijon mustard sauce. Michael Bao of Baoguette restaurant in New York shared this recipe with Martha.

The croque monsieur -- a grilled ham and Gruyere sandwich topped with rich cheese sauce -- becomes a croque madame when you add a fried egg. These knife-and-fork sandwiches will hit the spot on a cold day.

This twist on the BLT calls for crispy baked prosciutto slices instead of the traditional bacon. Layer the prosciutto on lightly toasted Italian bread with lettuce, tomato, and a garlic mayonnaise.

Inspired by calzones, these sandwiches are made by folding goat cheese, mozzarella, roasted tomatoes, and soppressata sausage into homemade pizza dough. Tuck a lightly dressed arugula and basil salad into the sandwiches just before serving.

Figs and goat cheese are a classic combination in salads, but here, the pair make a marvelous sandwich, joined by sweet caramelized onions. Enjoy these for lunch, or cut them into small wedges and serve as an appetizer.

The homemade chopped liver in this sandwich is enriched with caramelized onions and hard-boiled eggs. Schmear it on a fresh bagel or bialy with sour pickles.

Top-split buns are the time-honored choice for lobster rolls, but side-split buns can be used instead. While purists may insist on only mayonnaise or melted butter to dress the lobster meat, we think that some fresh chives and tarragon are a delicious addition.

A zesty topping of olives, anchovy, pickled peppers, and oregano crowns Italian cold cuts in this interpretation of the famous New Orleans sandwich. This recipe is from Sean Rembold of Marlow and Sons restaurant in Brooklyn, New York.

Kidney beans and rice are blended with ginger, garlic, carrot, broccoli, and cilantro to make these mini burgers inspired by Vietnamese banh mi sandwiches. Serve the pan-fried patties on whole-wheat rolls with chili mayonnaise, red onion, and sliced mango.

Savor the big, bold Italian flavors of homemade pesto, tapenade, roasted red peppers, prosciutto, and fontina cheese on this sandwich. Make it on a whole loaf of ciabatta and slice to serve four people.

These hot and hearty Mexican sandwiches are stacked with chicken breast, roasted poblano peppers, sauteed onion, cheddar and Monterey Jack cheeses, and crunchy jicama slaw. Drizzle the sandwiches with "crema" (Mexican sour cream) and serve with plantain chips.

Marinated artichoke hearts, roasted red peppers, pepperoncini, cannellini bean spread, and mortadella or prosciutto give this sandwich Italian flair. Assemble at least three hours ahead so the flavors have time to mingle.

This sandwich -- a cross between an Asian chicken salad and a Vietnamese banh mi sandwich -- gets crunch and color from a refreshing slaw of red cabbage and carrots dressed in lime juice and soy sauce. Spread a baguette with mayonnaise and layer with shredded chicken, slaw, and fresh cilantro and mint leaves.

Cooked quinoa adds a pleasantly chewy texture to cumin-spiced turkey patties. Tuck them into pita pockets with tahini sauce and sliced cucumbers.

Italian-style braised pork shoulder simmers in beer with pancetta, coriander, and fennel seeds. Pile the shredded meat onto rustic bread and top with warm, caramel-coated apple slices.

This hearty variation of the croque-monsieur -- a ham and Gruyere cheese sandwich cloaked in bechamel sauce -- includes roasted fingerling potatoes. The recipe comes from San Francisco's Tartine Bakery.

Sauteed baby artichokes, oil-cured black olives, tomatoes, parsley, and rich Taleggio or fontina cheese make a sophisticated sandwich. If artichokes are not in season, you may use canned or frozen artichoke hearts instead.

Combine softened butter with chopped anchovies, lemon zest, parsley, and chives to spread on these toasty pressed mozzarella sandwiches inspired by a traditional Italian appetizer. This recipe is courtesy of Sean Rembold from Marlow and Sons restaurant in Brooklyn, New York.

A favorite menu item at the legendary Russ and Daughters specialty-food store in Manhattan, this sandwich combines whitefish and salmon salad with horseradish-dill cream cheese on a fresh bagel. You can purchase the  wasabi-infused flying fish roe on their website.