Cook tortellini as directed on package. Drain.
Meanwhile, spray large nonstick skillet with nonstick cooking spray. Add bell pepper and onion stir-fry; cook over medium-high heat for 3 to 5 minutes or until tender, stirring occasionally. Add kielbasa; cook and stir 2 minutes.
Add pasta sauce; mix well. Reduce heat to medium; simmer 4 to 5 minutes or until thoroughly heated, stirring occasionally.
Add cooked tortellini; stir gently to mix. Cook until thoroughly heated, stirring occasionally. Sprinkle with cheese.