Heat oven to 375°F. Mix first 5 ingredients just until blended. Cut tops off peppers; remove and discard seeds. Fill peppers with meat mixture; place in shallow baking dish. Top with marinara sauce. Bake 50 min. to 1 hour or until meat mixture is done (160°F). Substitute: Substitute cooked long-grain brown rice for the quinoa.
Sponsor recipe courtesy of Miracle Whip® Dressing