Heat oven to 350°F. Grease a 2-quart casserole with shortening or cooking spray.
In a 3-quart saucepan, melt butter over medium heat. Cook green onions in butter 1 minute. Stir in flour and seasoned salt; cook and stir 1 minute. Remove from heat; stir in sour cream. Add peas, celery and bacon, stirring gently. Spoon mixture into casserole. Sprinkle with crushed crackers.
Bake 25 to 30 minutes or until center is hot and edges are bubbly.