Preheat oven to 375 F and line baking sheet with parchment paper.
In small skillet over medium heat, heat oil. Add onion and garlic; saute 1 minute. Add tomato paste and cook 1 minute. Transfer to food processor with walnuts, rice, roasted red peppers, breadcrumbs, Parmesan, Italian seasoning, parsley and egg. Pulse until combined but not mushy.
Form into eight equal balls and place on prepared baking sheet. Cook 12 minutes, or until firm to touch. Serve with sauce of choice.