Put the butter and oil into a deep, microwaveable dish. (At every stage of cooking, keep the dish uncovered and the microwave on high.) Place in the microwave for 2 minutes. Add the onion and garlic and stir to coat in the butter and oil. Microwave for four minutes. Add the rice, stir, then microwave for 4 minutes. Pour in 3 cups boiling water. Microwave for 9 minutes. Stir well, then microwave for 9 minutes more. Remove from the microwave and let sit, for 5 minutes, to allow the rice to absorb the rest of the water. Stir several times during the 5 minutes. Flake the Parmesan with a vegetable parer or sharp knife, then stir in. Add salt and pepper to taste, then serve hot.