Preheat oven to 350 degrees F
In a medium saucepan melt 3 tablespoon butter
Add flour and cook 1 minute.
Add salt, pepper, onion, and celery seed and stir
Stirring constantly, add milk or stock and bring to a low boil
Reduce heat and simmer 3 to 4 minutes or until mixture thickens slightly.
Add this mixture in a medium bowl along with corn, sour cream, and cheese. Stir.
Pour into an oven safe dish
Combine 1/4 melted butter and crushed butter crackers.
Evenly spread cracker mixture over casserole.
Bake at 350 degrees F 25 to 30 minutes or until edges are bubbly and crackers are toasted.*See post above for substitution suggestions.