Rempah-Malay Curry

• 12 sweet potato
• 6 garlic (cloves)
• 2 cube ginger (fresh)
• 1 onion (peeled)
• 1 capsicum pepper seeded (red)
• 1/2 chinese five-spice powder
• 1/4 chilli powder
• 1/4 lemon grass powder
• 140 gr yam (white peeled)
• 110 ml milk