Preheat oven to 350°F. Cook tortellini according to package directions, adding sugar snap peas and carrot for the last 1 minute of cooking; drain.
Meanwhile, in a 12-inch skillet melt butter over medium heat. Add mushrooms; cook about 5 minutes or until mushrooms are tender, stirring occasionally. Remove from skillet.
In a screw-top jar combine broth, flour, oregano, garlic salt, and black pepper. Cover and shake until smooth. Add to the same skillet; add milk. Cook and stir until thickened and bubbly. Add cream cheese; cook and stir until smooth. Remove from heat; stir in lemon juice.
Stir tortellini mixture, mushrooms, tomatoes, and sweet pepper into cream cheese mixture. Spoon into an ungreased 3-quart rectangular baking dish. Bake, covered, about 30 minutes or until heated through. Sprinkle with Parmesan cheese.