Sprinkle lamb with salt. Heat a large Dutch oven coated with cooking spray over medium-high heat. Add half of lamb, browning on all sides, and remove lamb from pan. Repeat procedure with remaining lamb.
Add onion to pan; sauté 4 minutes or until lightly browned. Stir in flour. Add lamb, wine, and garlic, stirring to combine. Cover, reduce heat, and cook 1 hour or until lamb is tender, stirring occasionally. Stir in the peppers; cover and cook 15 minutes or until lamb is tender, stirring occasionally.