Cook pasta according to package directions. Meanwhile, in a small saucepan, melt butter. Stir in the flour, bouillon, pepper and salt until smooth; gradually add milk. Bring to a boil; cook and stir 2 minutes or until thickened. Reduce heat; add cheeses and stir until smooth.
Stir in the turkey, asparagus and mushrooms. Cook until heated through. Drain pasta and place in a serving bowl. Pour sauce mixture over pasta; toss gently to coat.