Pour the stock into a large saucepan which has a lid and bring it to the boil over a high heat. Add the orzo, garlic granules, onion granules and salt.
Cover with a lid, then reduce the heat to medium-low and simmer, stirring often, until the liquid is absorbed and the pasta is cooked.
Add the mascarpone, Parmesan, parsley and black pepper, then stir it through. Taste for seasoning, then dish it up and serve with some more Parmesan for sprinkling over, if you’d like.