In a large mixing bowl, combine coconut milk, curry powder, minced garlic, grated ginger, salt, and sugar until smooth. Add chicken thighs, ensuring they are well-coated, and cover the bowl. Allow the chicken to marinate in the fridge for at least 1 hour, or up to overnight.

On a flat plate, mix together rice flour (or cornstarch) with a pinch of salt and pepper. Ensure even distribution.

Heat oil in a deep frying pot to 350°F (175°C). Dredge the marinated chicken thighs in the rice flour mixture and carefully fry for 5-7 minutes per side, or until golden brown. Drain on a wire rack.

In a small bowl, whisk together Thai chili sauce and plain yogurt until smooth. Adjust heat by adding more chili sauce to taste.

Toast the buns until golden. Spread the creamy sauce on both sides of each bun, layer with fried chicken, cucumbers, pickled carrots, and fresh herbs.

Garnish with fresh cilantro, a squeeze of lime juice, or crushed peanuts before serving.