Remove excess fat from meat. Cut meat into 1-inch pieces. Coat a 3 1/2- or 4-quart slow cooker with cooking spray.
Coat a large skillet with cooking spray. Brown half of the meat in hot skillet over medium heat. Remove meat from skillet.
Add oil to skillet. Brown remaining meat in hot oil. Drain off fat. Place meat, carrots, sweet pepper, and leeks in slow cooker.
Combine in a medium bowl 1 1/4 cups water, soy sauce, ginger, garlic, bouillon granules, and cayenne pepper. Pour over mixture in cooker.
Cover and cook on low-heat setting for 7 to 8 hours or on high-heat setting for 3 1/2 to 4 hours.
If using low-heat setting, turn to high-heat setting. Combine in a small bowl the cornstarch and water. Stir cornstarch mixture and frozen pea pods into mixture in cooker. Cover and cook for 15 minutes more or until sauce is thick and pea pods are tender. Stir in green onions.