Heat a saucepan over medium heat. When it is hot, pour in the olive oil. Add the garlic and onion; cook and stir until tender, about 3 minutes. Pour in the chicken stock and stir to loosen any bits from the bottom of the saucepan.
When the stock comes to a boil, stir in the risoni pasta. Reduce heat to low, cover the pan and simmer for 15 minutes or until pasta has absorbed all of the liquid. Stir occasionally to prevent sticking, especially towards the end. Season with salt and pepper before serving.