Sambal petai udang (spicy prawns with stinky beans)

Ingredients

• Rice bowl petai shelled from four
• 4 tablespoons oil
• 10 shallots, ground with one stalk lemon grass
• 2 tablespoons dried chilli paste
• 3 chili padi
• 1/2 teaspoon dried shrimp paste
• 1 tablespoon tamarind paste mixed with 250 ml water
• 200 g fresh prawns
• 1 large onion
• 1/2 to 1 teaspoon sugar
• Salt to taste