Ingredients

• 1 cup rice vinegar
• 1/2 cup sugar
• Kosher salt
• 1 2-inch piece peeled fresh ginger, sliced
• 2 carrots, cut into matchsticks (about 1 cup)
• 1/2 small daikon radish, cut into matchsticks (about 1 cup)
• 4 stalks lemongrass, finely chopped
• 1 shallot, thinly sliced
• 3 tablespoons soy sauce
• 3 tablespoons fish sauce
• 4 large skinless, boneless chicken thighs (1 1/4 to 1 1/2 pounds)
• Vegetable oil, for the grill
• 1 cup fresh cilantro
• 1 loaf soft French bread, split and cut into four 6-inch pieces
• 1/4 cup mayonnaise, preferably Japanese (such as Kewpie)
• 2 Persian or other small cucumbers, thinly sliced
• 1 jalapeno pepper, thinly sliced
• Sriracha, for serving

Instructions

1. Combine the vinegar, sugar, 1/2 cup water, 1 teaspoon salt and the ginger in a small saucepan and bring to a boil. Cook, stirring, until the sugar dissolves, about 2 minutes. Let cool.
2. Transfer half of the vinegar mixture to a large bowl and add the carrots and daikon; cover and refrigerate until ready to serve.
3. Transfer the remaining vinegar mixture to a shallow baking dish; stir in the lemongrass, shallot, soy sauce and fish sauce. Add the chicken thighs and toss to coat. Cover and refrigerate 2 hours, flipping the chicken halfway through.
4. Preheat a grill to medium high and brush the grates with vegetable oil. Remove the chicken from the marinade, scraping off the lemongrass and shallot; season with salt. Grill the chicken until well marked and cooked through, about 5 minutes per side. Remove to a cutting board.
5. Drain the carrots and daikon; stir in the cilantro. Cut the chicken thighs in half. Toast the bread on the grill and spread the mayonnaise on both sides; sandwich with the sliced cucumber, chicken, carrot mixture and jalapeno. Serve with Sriracha.