1. Boil cubed potatoes in 3 c. chicken broth.
2. Melt butter in stock pot, add flour and cook 5 minutes. Add onions, cook until soft.
3. Add enough broth from potatoes to evaporated milk in a measuring glass to make 3 cups. Add to roux (previous mixture) with 5 c. milk. Cook over medium-high heat until thick, stirring constantly.
4. Coursely mash half of potatoes. Add to milk mixture with cheese, sour cream, salt and pepper to taste. Add rest of potatoes and heat over very low heat 5 minutes. Garnish with shredded cheese, bacon and chives.