In a large bowl, stir together mayonnaise, sour cream, parsley, green onion, tarragon, dill, lemon juice, salt, pepper, and garlic powder. Add chicken, raisins, and almonds, stirring to combine.
Spread a thick, even layer of chicken salad onto 5 bread slices. Evenly divide cucumber slices among bread slices. Top each with remaining bread slice. Using a bread knife, cut crust from bread; discard. Cut each sandwich into 3 rectangular shapes.
Garnish each tea sandwich with thinly sliced cucumbers, or wrap each with a chive, if desired.
Recipe by Southern Lady Magazine at https://southernladymagazine.com/herbed-chicken-salad-tea-sandwiches/