Baked Potato Soup

I have made this soup quite a few times, and there is never any left over, it is awesome! I bake my potatoes the night before, to save time when making this soup.

2 med potatoes
3 tbsp butter
1 c diced white onion
2 tbsp flour
4 c chicken stock
2 c water
1/4 c cornstarch
1 1/2 c instant mashed potatoes
1 tsp salt
3/4 tsp pepper
1/2 tsp basil
1/8 tsp thyme
1 c milk

GARNISH:
1/2 c shredded cheddar cheese
1/4 c crumbled cooked bacon
2 green onions, chopped(green part only)

Preheat oven to 400. Bake potatoes 1 hour or until done. Cool.
Melt butter in large saucepan, and saute onion until light brown. Add the flour to the onions and stir to make a roux. Add stock, water, cornstarch, mashed potatoes, and spices to the pot and bring to a boil. Reduce heat and simmer for 5 minutes. Cut potatoes in half lengthwise and scoop out contents with a large spoon. Discard skin. Chop baked potato to make large chunks, about 1/2 inch in size. Add chopped potatoes and milk to the saucepan, bring soup back to a boil, then reduce heat and simmer the soup for another 15 minutes or until thick. Top each individual bowl with garnishes, and enjoy!