Cut potatoes into small chunks with onions and celery. Place in pot; cover with water and boil 7-8 minutes. While potatoes are cooking - melt butter, add flour to make a paste. Add milk and bring to boil.

Drain water from potatoes and add potatoes, celery, onion to milk mix. Put on low heat. Add shredded cheese, salt and pepper to taste. Stir until cheese is melted.