In a large bowl, combine coconut milk, curry powder, minced garlic, grated ginger, salt, and sugar to create a marinade. Add chicken thighs and refrigerate for at least 1 hour or overnight.

On a large plate, mix rice flour with salt and pepper for coating. Remove chicken from marinade, shake off excess, and dredge in the flour mixture.

Heat oil in a deep skillet to 350°F (175°C). Fry chicken for 5-7 minutes per side until golden brown. Drain on a wire rack.

In a separate bowl, mix Thai chili sauce and plain yogurt for the spread. Set aside.

Toast brioche buns. Spread chili mayo on both sides. Layer with crispy chicken, cucumbers, and pickled carrots.

Garnish with fresh cilantro and lime juice. Serve immediately.