Reginetti with Savoy Cabbage and Pancetta

reginetti or other short pasta

Kosher salt

olive oil

thinly sliced pancetta (Italian bacon)

small head of savoy cabbage, tough ribs removed, leaves torn

unsalted butter, cut into pieces

fresh thyme leaves

Parmesan, finely grated (about ½ cup)

Freshly ground black pepper

Poppy seeds (for serving)