Peel potatoes and cut into 1 inch cubes. Bring water to a boil, add potatoes and cook until tender. Drain, reserving liquid. Set aside potatoes. Measure 1 cup cooking liquid. set aside.
Peel and finely chop onion and add to butter melting in saucepan over medium heat. Cook, stirring frequently, until onion is translucent and tender.
Add flour to saucepan, season with pepper flakes and black pepper. Cook 3-4 minutes or until browned. Gradually add potatoes, reserved cooking liquid, milk and sugar to onion mixture. Add cheese and ham. Simmer over low heat 30 minutes, stirring frequently.
Consume massive quantities and then lie on couch and groan with pleasure!