Asparagus, Pancetta and Puff Pastry Bundles

small bunch (about 1/2 lb, 225 grams) asparagus, woody ends removed

parmesan cheese, grated

slices (2 oz, 56 grams) pancetta (see Note)

sheet puff pastry, thawed if frozen

olive oil

Salt and pepper

large egg + 1 tablespoon water, for egg wash