Heat butter or oil in large heavy saucepan. When warm, add rice and quinoa and toss to coat. Let toast in pan for a minute or two. Add broth and bring to a boil. Lower heat, cover, and cook for 18 minutes. If there is still liquid in the pan, continue to cook until the liquid has evaporated and the rice and quinoa are tender.

When the rice is cooked, add a little of the oil to pot and let cool to room temperature. Once the rice has cooled, add 1/4 cup olive oil and more if necessary. Rice should not be sticking together but not oily either. Add the remaining ingredients and refrigerate for several hours. Bring to room temperature before serving. Check seasoning and adjust, if necessary.