Country Style Potato Leek Soup

Cut off roots and tough dark green portion of leeks, leaving white portion and about 3 inches of light green. Slice in half lengthwise and chop into 1-inch sections. (You should have about 11 cups).

Heat butter in Dutch oven over medium-low heat until foaming; stir in leeks, increase heat to medium, cover and cook, stirring occasionally, until leeks are tender but not mushy, 15 to 20 minutes; do not brown. Sprinkle flour over leeks and stir to coat evenly ; cook until flour dissolves, about 2 minutes. Increase heat to high; whisking constantly, gradually add stock. Add bay leaf and potatoes; cover and bring to boil. Reduce heat to medium-low and simmer, covered, until potatoes are almost tender,
5 to 7 minutes. Remove pot from heat and let stand until potatoes are tender and flavors meld, 10 to 15 minutes. Discard bay leaf, season with salt and pepper; serve immediately.