Heat the oil and butter in a frying pan and sauté the shallots for 5 mins. Bring the stock to a simmer in a pan. Add the rice and lemon zest to the shallots and stir for 2 mins.
When the mixture is hissing in the pan, add the wine, reduce the heat, then add the stock, allowing 1 ladleful to absorb at a time.
Add the broccoli and half the Pecorino cheese with the last ladleful of stock. Cover, set aside for 5 mins, then serve with the remaining cheese and fresh parsley on top.
Notes
To stop the rice from sticking to the pan, keep stirring the stock into it as it cooks.