In 8-inch nonstick skillet, melt butter over medium-high heat. Add beef strips; sprinkle with garlic salt and pepper. Cook 2 to 3 minutes, stirring frequently, until browned.
Add mushrooms; cook 2 minutes, stirring frequently. Stir in broth, chili sauce and thyme. Cook 3 to 5 minutes, stirring occasionally, until flavors are blended.
Reduce heat to medium-low; stir in sour cream until well blended. Sprinkle with parsley. Serve over hot cooked noodles.