Step 1

Preheat the oven to 350°F.

Step 2

Coat a 9 x 13 baking dish with butter or cooking spray.

Step 3

In a medium stockpot, melt the butter over medium heat. Once melted add the diced onions and cook until softened.

Step 4

Add the minced garlic and cook for 1 minute.

Step 5

Add the flour and whisk for an additional 2-3 minutes.

Step 6

While whisking, slowly add the broth and milk. Continue to whisk until thickened, about 6-8 minutes.

Step 7

Season with salt and pepper, to taste. Remove from the heat.

Step 8

Add the thawed potatoes to the saucepan with the sauce. Add the sour cream, cheese, and green onions.

Step 9

Stir until well combined and pour into the prepared baking dish.

Step 10

Mix together the crushed crackers and butter until evenly moist. Spread on top of the potato casserole.

Step 11

Bake for 1 hour or until bubbly and lightly golden.