Whisk together soup mix and water in medium-size bowl; set aside.
Cook pasta according to package directions.
Meanwhile, heat oil in large skillet. Add sweet pepper and mushrooms; saute until partially tender, about 10 minutes. Stir in soup mixture. Increase heat to medium-high; cook, uncovered, until slightly thickened, about 8 minutes. Stir in 1/4 cup Parmesan, the parsley and the heavy cream; cook another 1 minute or until heated through.
Drain the pasta well; transfer the pasta to a large serving bowl. Add mushroom sauce and the remaining 1/4 cup Parmesan; toss to mix well. Serve the pasta immediately.