Bayou Shrimp Salad

2 tsps anchovy paste

1/2 teaspoon salt

1 teaspoon worcestershire sauce

1/2 teaspoon dry mustard

3 tsps tarragon vinegar

1 tsp dried tarragon

1 cup fresh parsley minced

6 green onions minced

1 cup mayonnaise

1/2 cup sour cream

1 teaspoon coarse black pepper

2 cups celery minced

2 lbs cooked shrimp small whole or halved

mixed garden greens