• Jump down to recipe
• More picnic recipes

Whether you're road tripping, picnicking or feeding the soccer team after a game, a crowd-pleasing sandwich is a winning concept. But the bumps along the way are fearsome. We've all had bad sandwiches: The bread is soggy. The fillings and condiments slip and slide. And discrete flavours often become murky and indistinguishable if a sandwich sits around too long.

It doesn't have to be this way. Pan bagnat, literally "bathed bread", is designed for just the kind of sitting around that would ruin a lesser combination. Leave it to the French to fill a loaf of crusty bread with tuna or anchovies, peppers, olives and more, and then bathe the sandwich in vinaigrette and wrap it up, letting its flavours develop over several hours. There is only one way this procedure achieves a glorious, sturdy-not-slimy sandwich: the bread. A baguette with a crackly shell of crust is imperative. Soft bread has no place here.

I began to ponder a variation on the traditional pan bagnat using charcuterie, vegetables and cheese. An antipasti cart spied at a nondescript restaurant sealed the deal. By adding vegetables in the form of eggplant caponata, bookending the meaty filling, I made sure there was no chance of a slippery mess. The sandwich pulled together like the long lost Italian cousin of the original French.

Caponata is more than a sandwich condiment. It's a relish, a side dish, a salad, a carry-me-to-work lunch with a hunk of bread and a wedge of cheese, and a celebration of agrodolce, that delicate balance of sweet and sour. Eggplant caponata recipes vary regionally: Some have nuts, others sport raisins, but I prefer to let the eggplant shine with not much more than tomatoes and a smattering of salty additions.

Buy big, unblemished, taut-skinned purple eggplant, as fresh as possible. Fresher means less potential for bitterness. While the ingredient list may seem long, it's more a pinch of this and a scoop of that, with most of them likely to be lurking in the pantry. Substitute at will: If there are no capers around, add more olives. Change up the vinegar to use that bottle you acquired on holiday. This is a bold condiment party that sings in sweet, salty, acidic tones.

One medium eggplant makes a good helping of caponata, about twice what's needed for the sandwich. Whiz half in the blender to make a spreadable condiment. Save the other half in its chunky form. Caponata has a long shelf life, at least a week, and refreshes with a drizzle of vinegar and a tiny sprinkling of sugar. It is possible to purchase jarred caponata, but freshly made has a crunch (from celery) unlike any in the jar.

Let's get back to the sandwich. Scoop out and form a trench down the centre of each side of the bread, and what goes inside will stay put. Arrange the fillings so the flavours blend yet assert themselves as individuals.

A pan bagnat benefits from a long marination before slicing for serving. Although this sandwich is often pressed, the Italian version is better left to mature without anything to weigh it down. Start the process with a plastic-wrap lined benchtop, open the bread like a book and set it atop that wrap, fill the trenches, and construct the sandwich. Once done, snugly wrap the baguette with the flavours trapped inside, and refrigerate overnight or carry it away in a picnic basket. By the time you've settled next to a stream and unfurled the blanket, the sandwich will be ready.

I'm partial to slicing the sandwich on the diagonal into five centimetre segments using a serrated bread knife. Keep the sandwich wrapped while slicing and then peel away the plastic and tuck the slice inside a picnic-perfect absorbent napkin. Serve with a light, bright red wine, then lie back and stare at the clouds.

Antipasti pan bagnat with eggplant caponata

A pan bagnat is a classic marinated sandwich that hails from the south of France. This rendition sends the sandwich on vacation to Italy where agrodolce – the play of both sweet and sour flavours – relish seasons a hearty, marinated, meaty sandwich fit for a crowd.

Make ahead: The caponata needs to sit for 2 to 3 hours at room temperature before serving or storing; it can be refrigerated up to one week in advance. Leftovers can be used with grilled meats and fish. If you make it ahead, refresh the piquant agrodolce with a splash of vinegar and a pinch of salt before serving. Assemble and tightly wrap this sandwich the night before or at least 8 hours in advance.

Ingredients

For the caponata

½ cup olive oil

450g eggplant, peeled and cut into 1cm cubes

1 tsp salt

1 medium red onion, cut into 1cm dice (about 1 cup)

3 celery sticks, halved and cut into 1cm dice (about 3/4 cup)

¾ cup canned no-salt-added crushed tomatoes

½ cup pitted Sicilian or other lightly cured green olives, chopped

¼ cup capers, rinsed and drained

1½ tbsp sugar, or more as needed

1½ tbsp red wine vinegar, or more as needed

¼ cup torn basil leaves

For the sandwich

1 baguette (350g to 450g)

12 slices hard salami

12 slices sopressata (12 slices)

8 slices prosciutto (8 slices)

8 round slices provolone cheese (about 170g), each cut in half

Method

For the caponata: Heat one quarter cup of the oil in a heavy, deep frypan over medium-high heat. Once the oil begins to shimmer, add half of the eggplant cubes. Cook for about eight minutes, until lightly golden brown tender, then transfer to a large bowl. Season with some of the salt.

Add 1½ tablespoons of the oil to the skillet, then add the remaining eggplant and cook it the same way (over medium-high heat). Scrape the eggplant and any oil in the pan into the same bowl. Season with the remaining salt and toss to coat.

Heat the remaining 1½ tablespoons of oil over medium heat in the same pan. Stir in the onion and cook for six to eight minutes, until translucent, then stir in the celery and cook for two or three minutes, just until it is crisp-tender.

Add the tomatoes, olives and capers to the onion in the frypan, then return all the eggplant cubes and their oil to the pan. Once the mixture is heated through and a few bubbles appear on the surface, make a well at the centre and add the sugar and vinegar. Stir until the sugar has dissolved, then blend that into the eggplant mixture; this is your caponata. Taste; the flavour should be assertively sour and sweet. Add a dash more sugar or vinegar, as needed. Stir in the basil leaves.
Makes about 4 cups; you will need 2 cups' worth for the sandwich.

Spoon the caponata into a bowl, drape with a clean tea towel and let the mixture cool and the flavours meld over the next 2 to 3 hours. Remove the towel and cover snugly with plastic wrap; refrigerate until ready to use. Bring to room temperature before serving.

For the sandwich: Put 2 cups of the caponata into a blender or food processor. Pulse to the consistency of a meaty spaghetti sauce (not completely smooth).

Cut the baguette in half lengthwise; tear out the soft insides of the baguette to accommodate the sandwich fillings. This will keep the sandwich from sliding apart. Generously fill the top and bottom hollows with the blended caponata.

Arrange slices of salami, sopressata and prosciutto on the bottom half of the baguette. Build a layer with the cheese half-slices. Repeat. Cover the meats and cheese with the remaining blended caponata, then place the upper half of the baguette on top to form the sandwich. Wrap it snugly with plastic wrap and refrigerate for at least eight hours, and up to overnight.

To serve, cut the sandwich (still wrapped) crosswise into 12 equal portions.

Serves 12

The Washington Post