Bring a large pot of water to the boil and cook the broccoli florets until soft.
Drain the broccoli well and then, using a potato masher, break them down. You do not need to make them smooth, as a bit of a bite can be pleasant.
To the mashed broccoli add the flour, parmesan, salt, black pepper, and egg and mix well, until uniform and without flour knots. The consistency will be thicker than the one of regular pancakes, but resist the temptation to add any liquid to the batter: the broccoli are full of it and will release some while cooking.
In a frying pan, add the olive oil, and warm-up; once it is warm, add ¼ of the broccoli batter to it, spread it evenly like a pancake (I do mine about 5mm thick), and allow to cook on a low flame. This will take, on a low flame, about 4 minutes on each side, so if you have a large pan, you may do two or more at the same time.
Once one side of the pancake is cooked, flip; allow to finish cooking through and through.