Mortadella 'sando' Recipe

Cook bacon

In a medium skillet set over medium heat, add diced bacon and cook until fat renders and pieces are crisp at the edges, about 6–8 minutes. Use a slotted spoon to remove most of the bacon pieces to a paper towel-lined plate, leaving about 1 tablespoon of bacon fat in the pan (discard excess or reserve for another use).

Sweat onions

Add the thinly sliced onion to the pan with the bacon fat. Reduce heat to medium-low and cook, stirring occasionally, until onions are soft and translucent, about 8–10 minutes.

Caramelize & season

Sprinkle brown sugar over the onions and continue cooking, stirring, until the sugar begins to melt and the onions take on a deep golden color, about 4–6 minutes more. Add apple cider vinegar and balsamic vinegar to deglaze, scraping up browned bits. Add the 2 tablespoons of water if pan looks dry to help lift fond. Stir in cooked bacon pieces, black pepper and 1/2 teaspoon of the salt, then reduce heat to low and simmer gently for 2–3 minutes so flavors meld. Taste and adjust salt (use remaining 1/2 tsp if desired). Remove from heat and set aside to cool slightly; jam will thicken as it cools.

Prepare pistachio mayo

In a small bowl, combine mayonnaise, whole-grain mustard and lemon juice. Stir in the coarsely chopped roasted pistachios, reserving a pinch (about 1/2 teaspoon) for final garnish. Season lightly with salt and pepper to taste. This yields a slightly crunchy, tangy spread.

Preheat a skillet or griddle over medium heat. Split the ciabatta rolls and brush cut sides lightly with the softened butter and a light brush of olive oil to help browning.

Place rolls buttered-side down on the hot skillet and toast until golden and crisp, about 1–2 minutes. Remove from heat.

Spread about 1 tablespoon of the pistachio mayo onto the bottom half of each toasted roll. Spoon 1 to 1 1/2 tablespoons of the bacon-onion jam over the mayo on each sandwich (divide jam evenly between the two sandwiches).

Layer 4 slices of mortadella on top of the jam on each sandwich. Place 1 slice of provolone (or fontina) over the mortadella. If you like the cheese slightly melted, return the assembled open sandwiches to the skillet, cover briefly (30–45 seconds) over low heat until the cheese softens — watch carefully so the bread does not burn.

Top with a small handful (about 1/2 cup distributed between sandwiches) of arugula if using, then sprinkle the reserved chopped pistachio over the arugula and top bun interiors. Close sandwiches, press gently, slice in half if desired, and serve warm.