Gary Farrell Sesame Crusted Crab and Mango Tea Sandwiches

1/4 cup plain yogurt
2 tablespoons vegetable oil 
cup fresh cilantro, chopped 
cup fresh mint, chopped
1 teaspoon kosher salt 
teaspoon crushed red pepper flakes
⅛ teaspoon freshly ground black pepper 
pound lump crabmeat (picked over) 
cup mango, finely diced
16 slices Pullman or white sandwich bread, cut -inch-thick, toasted
2 tablespoons sesame seeds, toasted (optional)

Whisk yogurt and vegetable oil in a medium bowl. Stir in cilantro and mint, kosher salt, red pepper flakes, and black pepper. Fold in crabmeat and mango. Thinly spread yogurt on one side of each slice of bread. Divide crab mixture among 8 slices; top with remaining bread, yogurt side down. Trim crusts. Cut each sandwich in half on a diagonal. Place toasted sesame seeds on a plate, if desired. Dip one cut side of each sandwich in sesame seeds.