Danish Creamery : Pork Banh Mi Burger

Ingredients

• ½ cup rice wine vinegar
• ¼ cup sugar
• 1 teaspoon Kosher salt
• 1 cup shredded carrots
• ½ cucumber, seeded and cut into matchsticks
• ½ cup mayonnaise
• 2 Tablespoons Sriracha chili sauce
• 1 ½ pounds ground pork
• 2 teaspoons grated ginger
• 1 Tablespoon fish sauce
• 1 Tablespoon soy sauce
• 1 teaspoon sugar
• 2 teaspoons cornstarch
• zest of 1 lime
• 2 Tablespoons Danish salted butter, softened, plus more for buns
• ½ cup chopped cilantro, plus more for serving
• freshly ground black pepper, to taste
• 4 hamburger buns, split
• lettuce leaves, for serving
• sliced jalapeño, for serving