Whisk together the fish sauce, sugar, lime juice, lemongrass and ginger and set aside.
Heat a heavy bottomed skillet over high heat and add oil.
Add ground chicken to the pan and press into a flat disc in the pan to get the most browning.
After 5-6 minutes flip the chicken over and crumble into small pieces with a metal spatula. Continue browning chicken until it is cooked through.
Stir in Herbies Thai spice Mix and turn off the heat.
Add half of the lemongrass sauce to the chicken and stir through.
Place butter lettuce leaves on a plate, fill with chicken mixture and top with cucumber slices, fresno chile slices, and mint.
Drizzle with the remaining sauce and serve.