Rinse and boil the chard in unsalted boiling water for about 10 minutes (if using a frozen product, cook it directly in water without defrosting). Drain, run under cold water, and squeeze with your hands to dry them. Then, roughly chop and keep aside.
Chop the pancetta or lardo di Colonnata, the parsley, and the spring onion separately with a knife. Set aside 50 g of pancetta.
Sauté the chopped parsley and spring onion gently for a few minutes in a pan with a bit of olive oil before adding 100 g of pancetta (if using garlic, warm the oil with one clove and remove it from the pan before adding parsley and spring onion).
Add herbs as well, allow to flavor for a few minutes while stirring, remove from heat, let cool, then incorporate Parmigiano, adjust salt, and mix well.