Heat oven to 350'. Spray 9x13 dish with spray/cut Kielsaba length wise then into 1/2 slices/brown kielbasa ove high heat until brown remove from skillet reduce to med heat cook onion and garlic 3-5 minutes until softened add spinach cook Until starting to wilt. layer half of hash browns in dish add 1 1/2 cups of cheese the kielbasa spinach mixture.add remaining hash browns . beat eggs & milk with whisk beat in mustard salt pepper pour over hash browns top with remaining 1/2 cup cheese.Bake 50-55 minutes or until golden brown top with chopped green onion