Bring a saucepan of salted water to the boil. Cook the broccoli for 8 minutes or until it just starts to soften. Remove the broccoli with a slotted spoon and set aside. Bring the water back to the boil, and add in the pasta and cook for 8 minutes or as directed on the packet. Drain the pasta in a colander reserving 1 cup of the cooking water.
Heat the oil and butter in a large frypan and add the pancetta. Cook the pancetta for 3 minutes until it starts to become golden and then add the garlic, anchovy and the chilli flakes.
Break up anchovy, then add the broccoli, breaking up the broccoli with the back of the spoon. Add in half of the reserved pasta water to moisten the dish, then season to taste with salt and pepper. Pour in the pasta and toss to combine with the sauce; you may need to add a little more water if it seems dry.
Transfer the pasta and broccoli to a serving bowl and scatter with grated parmesan, then serve.