Heat oil in a pan over medium heat. Add the sausage meat and cook, breaking up any lumps with a wooden spoon, for 4-5 minutes until browned all over. Meanwhile, dice onion and garlic.
Add onion and garlic, stirring, for 2-3 minutes until softened.
Add the rice, stock and half the lemon juice and bring to a simmer. Cover with a lid and reduce the heat to medium-low. Simmer for 20 minutes or until rice is almost cooked.
Preheat the broiler. Lightly beat eggs.
Remove lid from the rice and stir through egg, the parsley, 3/4 of the parmesan, and the remaining lemon juice.
Transfer the rice mixture to an ovenproof dish if necessary. Season to taste, then sprinkle remaining cheese on top and dot with butter. Broil for 5-6 minutes or until golden and lightly crisp.
