1. Place the lemongrass pieces in a plastic bag and use a rolling pin to gently crush the pieces, leaving them generally intact. In a medium skillet, heat the olive oil over medium heat. Add the crushed lemongrass, ginger and garlic to the skillet and sauté until fragrant and softened, about 4 minutes. Stir in the shrimp and cook for 2 minutes. Stir in the red pepper flakes and sauté for 3 to 4 additional minutes, until the shrimp are pink and cooked through. Remove from the heat, take out and discard the lemongrass pieces and set the shrimp aside to cool.

2. In a small bowl, whisk together the yogurt, buttermilk, chives, lime zest and lemon zest. Season with salt. Cut the cooled shrimp in ½-inch pieces and mix, along with the pan juices, into the yogurt-buttermilk mixture. Set aside.

3. Open the hot dog buns and brush one side with butter. In a medium skillet set over medium-high heat, place the buns outer-side down on the hot pan. Griddle for 2 to 3 minutes until browned, then turn over and repeat on the opposite side.

4. Spoon the shrimp mixture into the toasted buns and garnish with additional chives. Serve immediately with lemon wedges on the side.