Spray 3 1/2- to 4-quart slow cooker with cooking spray. In cooker, place onion and peppers. Top with beef. Sprinkle with chili powder, oregano, garlic and salt. Drizzle with lime juice. Add 1 cup of broth.
Cover; cook on Low heat setting 8 to 10 hours.
About 20 minutes before serving, cook quinoa as directed on package using 2 cups of beef broth.
Remove beef from cooker; place on cutting board. Shred beef with 2 forks; return to cooker and mix well.
Stir in black beans. Increase heat setting to High. Cover; cook about 15 minutes longer or until thoroughly heated.