Heat the oil in the bottom of a large skillet or frying pan set over a medium high heat and gently fry the onion, peeled and finely chopped with a pinch of salt until soft and starting to colour.
Add the beef and fry for about 10 minutes, breaking it up with the wooden spoon until it is cooked through and has browned in places.
Add the garlic, peeled and crushed along with the rice. Cook for another minute until the garlic is aromatic and the rice grains have heated through.
Add the white wine and turn the heat down to low. Allow the wine to bubble away completely.
For the egg lemon sauce, whisk together the egg yolks with the cornstarch into a thick paste, and gradually whisk in the lemon juice.
Strain the remaining cooking liquid and slowly whisk 200ml into the egg mixture.
Pour the mixture into the saucepan and return it to the low heat. Warm through the egg sauce, whisking often until it has thickened substantially.