Add 2 TBSP of flour and mix vigorously (make a roux)
Add in 3 bottles of clam stock
Add potatoes, (potatoes should be just covered with the clam stock) Cook until almost tender (10mins)
Add clams to soup
In a separate bowl, mix half and half and 2 TBSP of flour, mix until smooth
Add in salt and pepper and stir
Add half and half to soup when potatoes are done, let simmer until thickened
Season with more salt and pepper to taste
Notes
If you like a THICK chowder, add in more cornstarch or flour mixed with a little half and half. Please add the flour or cornstarch in a TBSP at a time and see if its to your liking. You do not want to have to add water to the soup, it will dilute the flavor.
If you like a more THIN chowder, add in 1 TBSP of flour or cornstarch mixed with a little half and half, instead of the 2 TBSP in the recipe above.