Chop bacon, cook with oil in a 5 quart sauce pan at a moderate heat until crisp. Take out the bacon and set aside (Note leave the oil in the pan it will become part of the compound roux.)

Add onions, celery and garlic and cook until tender or translucent

Add the flour to the pan to make the compound roux, stir in with a rubber spatula or wooden spoon for about 1 minute.

Add chicken stock and the milk stirring in with a whisk for 1 minute then use a wooden spoon or rubber spatula. Stir periodically to prevent burning.

Add the potatoes,salt and pepper and simmer for 20 minutes. The potatoes should be tender. Add the thyme 1/2 way through the simmering.

Add cooked bacon back in. Adjust the seasoning to taste with salt and pepper if needed. Add the cheese stir in to melt. Add parsley

Note-This soup can always have more bacon, a dollop of sour cream or cheddar sprinkled on top:)