Sweet potatoes & cabbage in coconut sauce

Ingredients

• 4 (abt 150g) small sweet potatoes - remove skin and quartered
• 1/2 (abt 160g) cabbage - cut into medium size pieces
• 1 calamansi lime - extract juice
• 1 cup fresh (carton) milk
• 1 cup water
• 3 tbsp oil
• salt to taste
• To Blend
• 3 tbsp dried prawns (soaked in water for 10 min first)
• 5 red chillies
• 5 shallots