Start water boiling for pasta.
Sprinkle chicken chunks with salt and pepper.
In a large saute pan over medium-high heat, add 2 tablespoons of butter. Once melted add chicken chunks and cook until no longer pink (8 minutes). Remove from pan.
Add remaining butter. Once melted add mushrooms, onions, garlic and parsley. Cook and saute until mushrooms are softened. Return chicken to pan and reduce heat to medium.
In a bowl, combine white wine, broth, dijon mustard, and cornstarch. Whisk thoroughly then pour into chicken mixture. Bring just to a bubble and reduce heat to medium-low. Cover with lid and let simmer.
Add pasta to boiling water and cook as directed on package. Drain in colander and shake off excess water.
Use a shallow pasta bowl to serve up a portion of noodles and a few ladles of chicken with gravy over top. Garnish with parsley if desired.