In a large bowl, whisk together coconut milk, curry powder, minced garlic, grated ginger, salt, and sugar. Add chicken thighs and marinate for at least 1 hour.

Combine rice flour with a pinch of salt on a plate. After marination, let chicken sit at room temperature for 10 minutes.

Heat vegetable oil in a deep skillet over medium-high heat until it reaches 350°F. Test readiness with flour mixture.

Dredge chicken thighs in rice flour and fry for 5-7 minutes per side until golden brown. Drain excess oil on paper towels.

In a small bowl, whisk together Thai chili sauce and yogurt until smooth.

Assemble sandwiches with buns, chili mayo, fried chicken, cucumbers, pickled carrots, and herbs. Top with the other half of the bun.

Serve with sweet potato fries or cucumber salad.