I had this at a salad bar once and knew I would be making it at home from then on!

1	Green onion	Chopped
1/2	Pkg. (about 2 cups)	Frozen peas
1/2	Cup	Mayonnaise
1/2	Cup	Sour cream
2	Tbsps.	Milk
1	Tbsp.	Sugar
1/2	Tsp.	Salt
1/2	Tsp.	Dried tarragon
1/2	Cup	Water chestnuts, sliced (optional)

Whisk mayonnaise, sour cream, milk, sugar, salt and tarragon together. Pour over peas and onion and fold to cover. Cover and let set overnight in the refrigerator. Serve cold.