Cook white rice in 2 cups chicken stock according to package directions.
Heat olive oil in skillet over medium high heat and add butter.
Saute onions until slightly softened and add garlic and mushrooms. Cook about three to five minutes, stirring as needed. Deglaze the pan by adding white rice and scraping the bits from the bottom of the skillet.
Bring to a boil and stir in peas, rice, and Parmesan cheese, reducing heat to medium. Add remaining chicken stock if needed and reduce until the stock is absorbed and the rice is slightly creamy.