1. Place turkey, bell pepper, 1 cup broth, soy sauce, garlic, red pepper flakes, and salt in slow cooker.
2. Cover and cook on LOW 3 hours.
3. Mix cornstarch with remaining 1/4 cup of broth in small bowl until smooth.
4. Turn slow cooker to HIGH.
5. Stir in green onions, peanut butter, and cornstarch mixture.
6. Cover and cook 30 minutes on high or until sauce is thickened and turkey is no longer pink in center and stir well.
7. Serve over noodles and sprinkle with chopped nuts and cilantro.