Ham and broccoli hash brown casserole

I have to write this one down before I forget what I did.  The original recipe is from my new no whine dinner book, but it called for a cream of celery soup.  I didn't have one, and I knew that when making my grocery list last week, but I also knew that I had seen a recipe for home made cream of celery soup in my $5 dinner mom cookbook, so I got that out. This turned out wonderful.  I loved it and am actually looking forward to my lunch left overs today.  I even think the kids all liked it for the most part.
The original recipe said to have all the frozen items thawed, but I didn't.  It still worked just fine.  They defrosted and heated in the oven.

Ingredients

• 1.5 Tablespoons butter
• 3 Tablespoons flour (I used wheat)
• 1 1/4 cup milk
• 1/4 cup vegetable stock (would have used 1/2, but didn't want to open another jar)
• 3 Tablespoons freeze dried celery (maybe 2 stalks chopped fresh?)
• 1 cup fat free sour cream
• 1/2 teaspoon onion powder
• 1/2 teaspoon garlic powder
• 1/2 teaspoon kosher salt
• 1/2 teaspoon pepper
• 1 30 oz bag frozen shredded potatoes
• 2 cups cheddar cheese (I didn't measure, but eyeballed it)
• 10-11 oz. frozen brocoli
• 8-10 oz diced ham (I used left over from Easter)

Directions

1. Preheat oven to 350.  Spray a 9 X 13 pan with cooking spray.
2. In a small saucepan, melt the butter.  Stir in the flour until it makes a paste and bubbles.  Whisk in milk and vegetable stock until flour has dissolved into the milk.  Add the celery, onion powder, garlic powder, salt and pepper.   Cook over medium heat for 5 to 6 minutes until thickened.  Remove from heat and stir in the sour cream.  
3. In a very large bowl, mix shredded potatoes, 1 1/2 cups cheese, broccoli and ham.  Stir in soup mixture.  
4. Spread evenly into the prepared pan.  (I was worried it wouldn't fit, but it did.)  Sprinkle with remaining 1/2 cup cheese.  Bake uncovered until heated through (about 45 minutes.)