"The greatest thing since sliced bread."

We've all heard and probably used the famous adage, and as transformative as that innovation was, to me it leaves out half (at least) of the equation — that is, everything that goes between those slices.

Yes, I'm talking about the sandwich. Without the filling, all you have with sliced bread is ... thinner bread.

There are about as many reasons to love sandwiches as there are ways to make them. They're portable and you can eat them with your hands. They're fast, easy and cheap to make. Oh, and they're fun!

That's where these recipes come in. If your familiar brown-bag sandwich has left you feeling kind of blue, fear not. We took five classic lunch sandwiches and gave them a boost. These updates won't make them unrecognizable or twee, but they will make them taste fresh, flavorful and special.

But first, a few sandwich best practices:

• Don't overstuff. Sure, you can put anything in a sandwich. That doesn't mean you should put everything in a sandwich. Being judicious with your filling means you can focus on a few quality ingredients. Plus, the sandwich will stand a chance of actually holding together.

• Incorporate flavors in high-impact, low-volume ways. There are plenty of strategies for amping up flavor without making your sandwich heftier. Whip up a flavored mayo (call it an aioli, if you like) by doctoring it with Sriracha, chipotle peppers, citrus zest and more. Incorporate a spice blend into yogurt. Repurpose bacon fat for toasting bread. You might be surprised how creative — and thrifty — you can be.

• Aim for a mix of textures. It's just as important as the right balance of flavors. Choose elements across a few categories, including creamy, crunchy, crispy, saucy and soft.

• Protect the bread. Insulate the bread when using wet fillings, or at least wait to assemble until you're ready to eat. Something fatty (butter, mayo) or a slice of cheese can do the trick. So does toasting the sides of the bread that will face the inside of the sandwich. This also gives your teeth something soft to sink into first.

• Protect the sandwich. Why go through the effort of making a sandwich only to pull it out of your bag smashed? Do yourself a favor and pack your homemade beauty in a hard-sided container or sturdy lunch bag. If you really want to be extra, wrap it in parchment or wax paper first.

Ready to assemble? Great. Try one of my custom creations and then start putting together some of your own.

BLT With Sriracha Mayo

Here's a sandwich where it doesn't pay to go too far off script. Good bacon, good tomatoes and good mayo, tweaked ever so slightly for extra flavor impact, turn this diner staple into a desk lunch worth savoring.

2 slices white bread

2 slices cooked thick-cut bacon, drippings reserved

1 tablespoon mayonnaise

1 teaspoon Sriracha

2 to 3 slices ripe tomato, sprinkled with salt

2 to 3 leaves green leaf lettuce

Brush one side of each slice of bread (something sturdy such as country or hearty white) with the bacon drippings. Toast the greased side for a few minutes, either in a skillet or under the broiler set on high, until golden brown. In a small bowl, mix together the mayo — Duke's or bust in my house — and Sriracha. Spread half the Sriracha mayo on each of the toasted bread sides, then assemble the bacon, tomato and lettuce between the slices of bread.

Variations: peach instead of, or in addition to, tomato. Leave the Sriracha out of the mayo. Try a different kind of lettuce — classic iceberg and butter are both good.

RELATED: A love letter to Duke's Mayonnaise

Crunchy Raspberry PB&J

A peanut butter and jelly is so easy to make and so easy to mess up. I wanted to resist the temptation to turn it too fancy and precious, but a few simple upgrades gave me a satisfying, well-balanced sandwich I wish I'd had packed in my school lunch bag.

2 to 3 tablespoons crunchy natural peanut butter

2 slices whole-wheat bread

2 tablespoons raspberry jam or preserves

2 to 3 thick (about ¼ inch) slices tart apple

Divide the peanut butter between the slices of bread. Spread the raspberry jam on top of one of the peanut butter layers. Place the apple slices on top of the jam, followed by the other slice of bread.

Variations: Use fig preserves. Try a different crunchy nut butter. Make it a club with another slice of bread and more filling.

Spicy, Smoky Turkey Sandwich

Chipotle mayo and smoked turkey will remind you of the outdoors even if you are eating it at your desk. Another boring turkey sandwich? Never again with this zesty number.

1 chipotle in adobo, drained and minced

3 tablespoons mayonnaise

2 slices sourdough bread

1 slice pepper jack cheese

4 ounces smoked turkey

Handful baby spinach leaves

In a small bowl, combine the chipotle and mayonnaise. You'll need about a third of it (or as much as you want) for this sandwich; the rest will keep in the fridge for a few days. Spread half of the reserved mayo on one side of each slice of bread. Assemble the cheese, turkey and spinach between the slices of bread.

Variations: Decrease the chipotle or leave it out of the mayo. Swap in Monterey Jack, or any deli sliced cheese, for the pepper jack. This would also be good on a kaiser roll.

Dill and Pickle Egg Salad Sandwich

I prefer a mustard-based salad over a mayo-based one, so I pulled inspiration from my potato salad recipe (based on a Mark Bittman original). The eggs worked great in lieu of potatoes, with the dill, pickles and rye bread coming together for a very punchy sandwich.

¼ cup extra-virgin olive oil

1 tablespoon brine from a jar of cornichons, gherkins or other small pickles, plus more as needed

1 ½ teaspoons white or red wine vinegar, plus more as needed

½ teaspoon mustard, such as Dijon

1 tablespoon honey, plus more as needed

Kosher salt

Freshly ground black pepper

2 hard-boiled eggs, diced

3 cornichons, gherkins or other small pickles, finely chopped

2 teaspoons minced fresh dill

2 slices rye bread

Handful mixed baby lettuces

Combine the oil, pickle brine, vinegar, mustard and honey in a mini food processor or lidded jar you can shake. Season lightly with salt and pepper. Process, or seal and shake, to form a creamy vinaigrette. This should take 1 minute or less. Taste and add more brine, vinegar or honey, as needed.

Combine the egg, cornichons and dill in a medium bowl. Add 2 tablespoons of the dressing. Tuck the egg salad into the bread in between two thin layers of lettuce.

Double Mango Curry Chicken Salad

A double dose of mango — fresh and chutney — goes into this aromatic salad inspired by Washington chef Scott Drewno. My version is based on a yogurt dressing reminiscent of a tandoori marinade. There's no need to cook a chicken unless you want to, because this is the perfect use for a store-bought rotisserie bird.

This recipe scales up easily if you want to make enough chicken salad for a few days.

Note: Toast the almonds in a small dry skillet over medium heat, tossing frequently, until fragrant, 3 to 5 minutes.

3 tablespoons whole milk Greek yogurt

½ teaspoon curry powder

1 tablespoon olive oil

Squeeze fresh lemon juice

Pinch kosher salt

Pinch sugar

3 to 4 ounces cooked chicken, torn into 1- to 2-inch pieces

1 tablespoon chunky mango chutney, such as Major Grey's

1 tablespoon toasted slivered almonds

2 tablespoons diced mango

2 or 3 leaves butter lettuce

2 slices challah

In a medium bowl, whisk together the yogurt, curry powder, olive oil, lemon juice, salt and sugar. Stir in the chicken, chutney, almonds and diced mango. Pile the chicken salad on top of the lettuce in between the slices of challah.

Variations: Use cucumber instead of mango. Opt for another kind of nut. Change the flavor profile with a different spice blend. Try in a wrap or pita.

RELATED: Who makes the best rotisserie chicken in Austin?