large, ripe Italian sweet peppers
1 7-ounce jar imported tuna in olive oil separated into small chunks, oil reserved
1/4 cup salt-packed capers rinsed thoroughly
30 mixed olives green and black, pitted and chopped
2 large garlic cloves finely chopped
6 ripe (roma or the like) tomatoes halved, seeded, and roughly chopped into small pieces
1/2 cup unflavored breadcrumbs plus extra for sprinkling
1/4 cup Parmigiano-Reggiano cheese plus extra for sprinkling
2 tablespoons extra-virgin olive oil plus extra for drizzling
caciocavallo cheese provolone, or any other type of stretched-curd cheese, for grating
Preheat the oven to 400°F Using a sharp paring knife, trim off the tops of the peppers, about 1/2-inch below the base. Scrape away any inner seeds and membranes. Place the peppers in a colander and rinse well under cold running water. Remove and roughly chop 5 of the peppers into small pieces and set the rest aside to drain. In the bowl of a food processor, combine the tuna, reserved oil, capers, olives, garlic, and half of the tomatoes. Pulse until the ingredients are smooth. Sprinkle in the bread crumbs, parmigiana, and olive oil and pulse until well combined. Add the chopped peppers and remaining tomatoes and pulse briefly just to combine. Or else, you can use a hand blender to combine the ingredients in a large bowl, if you prefer. Using a cookie making gun or a pastry bag, fitted with a wide round tip, fill the peppers with the stuffing. Smooth the surface of the stuffing and place the peppers on a lightly oiled baking sheet. Sprinkle the surface of the peppers with bread crumbs and parmigiana. Grate some caciocavallo cheese over the top and drizzle with a little olive oil. Place the baking sheet in the oven and bake until the peppers are lightly charred and beginning to collapse, about 15 to 20 minutes. Serve hot, warm, or at room temperature.