Heat oil in a large saucepan over medium heat.
Saute quinoa and onion, stirring constantly, for 3 minutes. Add bell pepper; saute 2 minutes.
Stir in 2 cups water, soy sauce and rosemary. Bring to a boil, cover, and simmer for 15 minutes or until water is absorbed.
Check after 10 minutes; if quinoa is almost dry, add additional 1/4 cup water.
Add peas and walnuts. Remove from heat, cover and set aside for 10 minutes.
Add salt and pepper to taste.