Heat a large skillet over medium-high heat with EVOO, a couple of turns of the pan.
Add the beef, season with salt and pepper, and brown. Add the salami and brown. Add the onion, garlic, chiles, Cubanelle pepper and oregano and stir to soften, about 5 minutes. Add the tomato paste, stir a minute more, then add the passata or tomato sauce, stock and wine, reduce the heat and simmer 20 to 30 minutes to thicken. Cool and store. Reheat over medium heat with a splash of water or stock to loosen up.
To serve, finely chop the giardiniera and parsley in a food processor or by hand to make a relish. Lightly toast or warm the rolls in the oven. Serve the sloppy mix on the rolls, topped with the relish.