- 4 lbs yukon gold potatoes, thinly sliced – about 1/8 inch (no need to peel!)
- 1/2 yellow onion, diced
- 3 garlic cloves, minced
- 4 tablespoons unsalted butter (half of a stick)
- 4 tablespoons all purpose flour
- 1 3/4 cup 2% skim milk
- 1 cup chicken stock
- 2 teaspoons coarse salt
- 1/2 teaspoon fresh ground black pepper
- 1 cup cheddar cheese, grated
- 1 cup parmesan cheese, grated
- Thinly sliced chives and fresh ground black pepper to garnish
- Preheat oven to 400˚F. Grease a 9X13 baking dish.
- In a large skillet, melt butter over medium high heat. Add onion and saute, stirring occasionally, until softened, about 5 minutes.
- Add the garlic and saute, stirring frequently, until fragrant, about 1 minute.
- Whisk in flour and cook 1-2 minutes, until flour is golden.
- Add chicken stock, salt and pepper and stir until smooth. Slowly pour milk into the skillet mixture, stirring as you pour. Bring to a simmer and reduce heat to low. Simmer for 1-2 minutes, until slightly thickened. Remove from heat.
- Layer half of the sliced potatoes into the casserole dish. Pour half the skillet sauce over the potatoes. Sprinkle with half of the cheddar and half of the parmesan cheese.
- Layer the remaining potatoes on top. Pour the rest of the skillet sauce over the potatoes and sprinkle with the remaining cheeses.
- Cover the dish with aluminum foil. Bake for 30 minutes. After 30 minutes, remove the aluminum foil and bake another 30 minutes, until potatoes are cooked through and the sauce is bubbling.
- Let cool 5 minutes. Garnish with chives and fresh ground black pepper. Serve warm.