Place potatoes in a saucepan, and cover with cold water to 2 inches above. Add 1/4 teaspoon salt; bring to a boil. Reduce heat, and simmer 15 minutes or until tender; drain. Return the potatoes to pan over low heat; add remaining 1 teaspoon salt and butter to pan. Mash the potatoes with a potato masher to desired consistency.
Add cheese and pepper to potato mixture; stir until cheese melts. Stir in milk; cook 1 minute or until thoroughly heated, stirring frequently. Remove from heat; stir in parsley.