8 Tbsp cold unsalted butter, divided
4 Tbsp all-purpose flour, divided
¼ tsp poultry seasoning
¼ tsp onion powder
¼ tsp garlic powder
½ tsp kosher salt
½ tsp fresh ground black pepper
½ cup milk
1 cup low-sodium chicken broth, divided
½ cup chopped onions
1 (26 oz) package frozen shredded hash browns
1 (8 oz) package shredded colby cheese
Preheat oven to 375 °F.
In medium sized saucepan, over medium heat, melt 2 tablespoons butter. Once butter is melted add 2 tablespoons flour and all seasonings. Whisk to create a paste. Add milk, whisking as you pour. Whisk until completely combined.
In a quart sized mason jar combine 2 tablespoons flour and chicken broth. Seal tightly and shake the living tar out of your mixture. You will create a smooth flour mixture for thickening your sauce called a slurry.
Slowly pour slurry into mixture, whisking constantly. Bring to a boil and cook 2 minutes, stirring constantly.
Pour soup into 9x13 casserole dish. Add remaining 6 tablespoons butter and onions. Stir until butter is melted. This will also start to cool your soup. Add cheese and frozen hash browns. Mix well with a spoon.
Bake 25 minutes or until the top is golden brown.