Step 1: Soak 12 bamboo skewers in cold water for 30 minutes. Heat the olive oil in a small frying pan and cook the shallot and chilli for 3-4 minutes until softened. Remove from the heat and add the soy sauce, sugar, lime juice and curry paste. Put aside to cool.
Step 3: Cut the chicken, sirloin steak and pork tenderloin each into 4 strips. Put into a non-metallic bowl and pour over the marinade. Toss well and marinate covered for 1 hour at room temperature.
Step 5: Making the peanut butter sauce:
Step 6: Heat the oil in a saucepan and cook the chilli, garlic and lemon grass for 2 minutes until softened. Add peanut butter, coconut milk, lime juice and sugar; simmer gently for 2-8 minutes until thickened and chilli powder to taste. Be careful with the heat as it separates the sauce very easily. Keep warm.
Step 8: Remove the strips of chicken and meat from the marinade and thread onto the skewers. Discard marinate. Grill on a barbecue over direct high heat for 6-8 minutes on both sides, turning once. Serve with the warm peanut sauce.