Prepare pasta according to package directions, adding chicken bouillon cubes to water.
Meanwhile, melt 4 Tbsp. butter in a large skillet over medium heat. Add sliced mushrooms, and sauté 5 minutes or until liquid evaporates and mushrooms are golden brown. Remove from heat. Stir in chopped parsley, noodles, and remaining 1 Tbsp. butter. Stir in pepper to taste.
*1 (8-oz.) package assorted mushrooms, sliced, may be substituted.