Heat a large nonstick skillet coated with cooking spray over medium heat. Add sausage, and cook 3 minutes or until browned, stirring often. Remove sausage from pan, and keep warm.
Separate onion wedges into layers. Recoat pan with cooking spray. Add onion; and cook 3 minutes or until browned, stirring frequently. Increase heat to high, and add water to pan; bring to a boil. Add rice, seasoning packet, oregano, and red pepper. Return to a boil; cover, reduce heat, and simmer 4 minutes or until liquid is almost absorbed. Stir in reserved sausage and peas.