Heat a grill to medium high heat.
Cut meatballs in half, and flatten into an oval.
Slice the zucchini lengthwise, very thin, on a mandolin or with a very sharp knife, and roll it up end to end.
Slice the jalapeños on a long angle, and quarter the onion.
Using metal skewers, or well soaked bamboo ones, thread one oval of meatball, followed by one slice of jalapeño, one large piece of onion, another piece of jalapeño, and finally one piece of rolled zucchini.
Repeat the process until the skewers are full, then reserve, covered in the refrigerator.
To make the salsa verde, combine the parsley, basil, mint, shallot, garlic, capers, crushed red pepper, red wine vinegar, anchovy, and the olive oil in the bowl of a food processor and chop until a mostly smooth sauce forms and transfer to a bowl.
Lightly brush the spiedini with some of the salsa verde, and grill until the meatballs reach an internal temperature of 165ºF, turning often to avoid burning.
Transfer the skewers to a plate and cover loosely with foil and allow to rest for 3-5 minutes.
While the spiedini are resting, quickly warm the flatbread on the grill, place the meat and vegetables onto the bread, drizzle with a generous amount of salsa verde, and top with shaved parmesan.
Wrap up the sandwich and enjoy immediately.