Potato Soup

1 cup onion - minced
1 cup celery " "
6 cups potatoes - chopped
4 cups milk
2 sticks butter
2 chicken bullion cubes
1/2 t thyme
1/2 t pepper
Salt to taste
Bacon bits

Using 3 - 4 quart pot, saute onions and celery in butter. Add potatoes and bouillon. Simmer until potatoes are cooked on low heat.
In a separate pan, add 4 T flour and 4 T butter. Stir. Heat until butter is melted.
Stir into soup. Add heated milk. Stir until thickened. Add salt, pepper and thyme.
Garnish with bacon bits and cheese if desired.