In a large saucepan, combine chopped potatoes, water, bouillon granules, ground red pepper, and black pepper. Bring to a boil; reduce heat. Cover and simmer about 10 minutes or till potatoes are just tender, stirring occasionally.
Stir in 2-1/2 cups of the milk and the corn. In a small bowl, stir together remaining 1/2 cup milk and flour; stir into potato mixture. Cook and stir over medium heat till slightly thickened and bubbly. Cook and stir for 1 minute more. Add cheese; stir till melted. Spoon into 4 soup bowls. Top each serving with parsley.