Thaw scallops, if frozen. Cut any large scallops in half.
In a 4-1/2-quart Dutch oven bring 3 quarts water to boiling. Add pasta; return to boiling. Cook for 5 minutes. Add mushrooms, carrots, and green onions. Return to boiling. Cook, uncovered, for 5 to 7 minutes more or until pasta is tender but slightly firm and vegetables are crisp-tender. Drain pasta and vegetables; keep warm.
Meanwhile, in a small mixing bowl stir together wine, cornstarch, and bouillon granules; set aside.
In a large skillet melt margarine or butter. Add garlic; cook over medium-high heat about 1 minute. Add scallops, wine mixture, parsley, and lemon-pepper seasoning to skillet. Cook and stir over medium heat until thickened and bubbly. Cook and stir for 1 to 2 minutes more or until scallops turn opaque.
Arrange pasta mixture on individual plates or a large platter. Spoon the scallop mixture over pasta mixture. Makes 4 main-dish servings.