Ingredients (~6 servings)
- 3 Tbsp butter
- 1/4 cup all-purpose flour
- 1 1/4 tsp salt
- 1/4 tsp black pepper
- 2 1/2 cups whole milk
- 2 1/4 lbs potatoes, peeled and sliced into 1/8″ slices
- 1/2 large onion, thinly sliced
Create the Cream Base
Preheat the oven to 350F, grease a 9×9″ baking dish.
In a medium saucepan melt the butter on medium heat, then add the flour, salt and pepper, whisking until smooth; this is your roux.
To eliminate any possibility of the mixture developing lumps, whisk in about 1/2 cup of the milk first to get the roux smooth. Then, slowly continue whisking in all of the milk until smooth.
Continue stirring the mixture over medium/medium-low heat while bringing to a boil, the mixture will thicken up significantly after about 3 to 4 minutes boiling time. Once the mixture coats the back side of a spoon, remove it from the heat.
Layer the Potatoes and Onions
Place 1/3 of the potato slices in the bottom of the prepared baking dish, slightly overlapping.
Top with 1/3 of the onion slices and drizzle 1/3 of the cream sauce on top.
Repeat this same procedure two additional times for potatoes, onions, and cream sauce, finishing with cream sauce on the very top.
All of the potatoes on the top layer do not have to be completely covered with cream sauce, but it is very important to make sure that all of the edges are covered; otherwise, the edges could dry out.
Baking Until Fork Tender
Cover the baking dish loosely with foil and place in the preheated oven for approximately 75 minutes.
At the end of this time period, remove the foil and bake for another 15 minutes; this will allow the top to brown slightly.
The potatoes should easily break or pierce with a fork when properly cooked. If they still feel firm, continue to bake them in the oven until they test fork tender; test them in 10-minute intervals until they are fork tender.
Let the baked potatoes rest for approximately 10 minutes before serving; as the baked potatoes cool down, the sauce will continue to thicken.
Scalloped Potatoes
Ingredients
~6 servings
- 3 Tbsp butter
- 1/4 cup all-purpose flour
- 1 1/4 tsp salt
- 1/4 tsp black pepper
- 2 1/2 cups whole milk
- 2 1/4 lbs potatoes peeled and sliced into 1/8″ slices
- 1/2 large onion thinly sliced
Instructions
- Preheat oven to 350F and grease 9×9 baking dish.
- Melt butter in saucepan, whisk in flour, salt, and pepper to make roux.
- Gradually add milk, whisking to prevent lumps.
- Bring sauce to boil, stirring until thickened, about 3-4 minutes.
- Layer 1/3 potato slices in dish, overlapping.
- Top with 1/3 onion slices and 1/3 cream sauce.
- Repeat layering twice more, ending with sauce covering potatoes.
- Cover with foil and bake 75 minutes.
- Remove foil, bake 15 more minutes until top browns.
- Test potatoes with fork for tenderness.
- Let rest 10 minutes before serving.
