Soak bamboo skewers in water for at least 2 hours.

In a large bowl, combine sliced beef rump steak with baking soda, coconut milk, red curry paste, curry powder, white sugar, and dark soy sauce; cover and refrigerate overnight.

Remove beef from refrigerator and thread approximately four pieces onto each soaked skewer.

Heat a non-stick pan over medium-high heat and add a splash of vegetable oil; cook skewers for 8-10 minutes, turning frequently.

In a saucepan, combine natural peanut butter, coconut milk, cider vinegar, and remaining marinade; heat over medium-low until thickened.

Serve skewers with peanut sauce and garnish with peanuts, coriander, and chilies.