Creamy Spinach Casserole

Ingredients

• 4 tablespoons butter 
• 10.8 ounce campbell's® condensed cream of celery soup canned
• 1 tablespoon flour all-purpose
• 20 ounce pkt spinach frozen thawed drained chopped
• 0.5 teaspoon garlic salt 
• 1  onion diced finely
• 10 servings salt and pepper to taste

Equipment

• sauce pan
• whisk

Directions

1. In a saucepan, combine celery soup, flour, butter or margarine, garlic salt, salt and pepper, spinach and onion.
2. Whisk together and cook over medium heat until hot and thick.