Bring a large pot of lightly salted water to a boil. Add tortellini. Cook, stirring occasionally, until tortellini float to the top and the filling is hot, about 5 minutes. Drain.

Heat vegetable oil in a large skillet over medium heat; cook and stir chicken breast in hot oil until no longer pink in the center, about 10 minutes. Remove from heat.

Melt butter in another skillet over medium heat; cook and stir mushrooms and garlic powder until mushrooms begin to soften, about 3 minutes. Stir heavy cream into mushrooms and bring to a boil. Reduce heat to medium-low and simmer until slightly thickened, about 3 minutes. Add Parmesan cheese, parsley, and salt. Continue to cook until cheese is melted, about 1 minute.