In a large saute pan, over medium heat, add the olive oil. When the oil is hot, add the onion and season with salt and pepper. Saute for 3 minutes, or until the onions are slightly soft. Add the rice and saute until until it is evenly toasted. Add the duck rillette and saute for 2 minutes. Add the garlic and 1/3 of the stock. Bring the liquid to a boil and reduce to a simmer. Cook for 6 minutes or until almost all the liquid is absorbed, stirring occasionally. Add 1/3 more stock and simmer for 6 minutes, stirring occasionally, add the remaining stock and simmer for another 6 minutes or until the mixture is creamy and bubbly. Add the butter, cream, cheese and green onions. Reseason with salt and pepper. Simmer for 2 minutes and serve immediately.