Gouda Potato Casserole

Potato Casserole with Gouda, Garlic, and Thyme

8 ounces Gouda cheese, shredded (about 2 cups)
4 medium garlic cloves, minced (1 1/2 tbsp)
4 tsp minced fresh thyme leaves
2 tbs butter
1/4 cup all purpose flour
3 1/2 cups chicken stock/broth (vegetable stock would work if you
dont have, maybe even milk although I havent tried it and would
change the taste a LOT)
1 bay leaf
2 lbs Yukon gold potatoes, peeled and sliced 1/8 inch thick
2 lbs russet potatoes, peeled and sliced 1/8 inch thick
3/4 tsp salt (sea salt is real good, even "kosher" salt)
3/4 tsp ground black pepper

1. Put one oven rack to the lower middle position and second oven rack
to highest position; heat oven to 400 degrees. Toss together cheese,
garlic, and thyme in a small bowl, set aside.

2. Heat butter in medium saucepan over medium heat until foaming; whisk
in flour and cook until golden and bubbly, about 30 seconds (*note--
this is called a roux). Whisking constantly, gradually add chicken
broth or water. Increase heat to high, add bay leaf, and bring to a
boil. Reduce heat to medium and simmer, stirring occasionally, until
mixture thickens, about 2 minutes. Off heat, remove and discard bay
leaf; cover to keep sauce warm.

3. Alternating Yukon gold and russet slices, arrange a third of the
potatoes in overlapping rows. Sprinkle potato layer evenly with 1/4
tsp salt, 1/4 tsp pepper, and a third of cheese mixture. Make a
second layer with the same amount of potatoes, salt, pepper, and cheese.
Make a third layer with the same amount of potatoes, salt and pepper,
but reserve the cheese remaining. Pour warm sauce over potatoes,
tilting pan side to side to distribute evenly. Cover with foil and
bake on lower middle rack 45 minutes. Remove foil and continue to bake
until potatoes are tender, about 45 minutes longer. Remove potatoes
from oven and spriknle with remaining cheese; bake on highest rack
until cheese is golden brown, about 5 minutes. Cool 10 minutes and
serve.