Prepare couscous according to package directions. Keep warm.
Heat pecans in a large nonstick skillet over medium-low heat, stirring often, 3 to 4 minutes or until toasted. Remove from skillet.
Remove casing from sausage, and cut into 1/2-inch slices.
Heat skillet or wok at medium-high heat 1 minute. Add sausage, and stir-fry 7 to 8 minutes or until done and no longer pink.
Add bell peppers, onion, and garlic to skillet, and stir-fry 3 to 4 minutes or until tender. Add plums and apples, and stir-fry 1 1/2 to 2 minutes. Stir together chicken broth and next 5 ingredients until cornstarch is dissolved. Add to sausage mixture, and bring to a boil. Boil 1 to 2 minutes or until thickened. Serve over couscous. Sprinkle with toasted pecans.