Baked Cheesy Scalloped Potatoes

2 Tbs. unsalted butter
1/2 cup yellow onion, finely chopped
1 clove fresh garlic, finely minced
2 Tbs. whole-wheat flour
Few dashes fresh black pepper
Dash of sea salt
1-1/4 cup milk
1 cup Sharp Cheddar cheese, shredded
1 Lb. Russet potatoes, peeled and thinly sliced into circles

Preheat oven to 350 degrees F. Grease a 1-1/2 quart casserole dish and set aside.

In a small saucepan, melt butter. Stir in onions and garlic, and cook over medium heat, until tender but not brown.

Whisk in flour, pepper, and salt. Add milk all at once, whisking to combine. Continue to cook over medium heat, uncovered, until mixture is thickened and bubbly. Once thickened, add the cheese and stir until melted.

Place a layer of potatoes in the bottom of the casserole dish. Lightly sprinkle with a dash of salt. Ladle a spoonful of the sauce evenly over the potatoes. Continue to layer sauce and potatoes (lightly salting each layer of potatoes only), ending with sauce on the top.

Bake, covered, for 40 minutes. Then, uncover and bake an additional 30 minutes, or until the potatoes are fork-tender and golden on top.