These decadent scalloped potatoes are layered with a creamy cheesy sauce and are the perfect side dish for your next holdiday or special occasion meal.
Preheat oven to 375°F and spray a 9x13 baking dish with cooking spray.
Melt the butter in a large skillet over medium heat. Add the onion and cook for 3-4 minutes until translucent. Add garlic and cook for another minute. Then add flour and cook for 1-2 minutes, stirring frequently, until light brown.
Add the milk and broth whisking constantly for around 1 minute until the mixture is smooth. Bring to a low simmer and stir occasionally for another 4-5 minutes until thickened. Remove from heat and stir in ½ cup of cheddar cheese and season with salt and pepper.
Spoon a thin layer of the sauce into the baking dish and spread evenly. Add a single layer of potatoes, slightly overlapping. Top with around ⅓ of the sauce then ½ cup of cheese. Repeat for 2 more layers.
Bake uncovered for around 1 hour until potatoes are tender. If top begins to brown too much during cooking you can loosely cover with foil.
Let stand for around 10-15 minutes before serving.