Blend all the spice ingredients in food processor until fine.
Scald banana leaf in boiling water to soften it and pat it dry. You may need to trim the leaf to square size. If you don’t know how to fold the leaf into a pouch shape, an easier alternative is to use a small metal bowl.
In a bowl, pour in the blended spice paste and all other ingredients except Thai basil leaves. Mix well till smooth
Place a few of Thai basil leaves on the prepared banana leaf and then lay the mixture on top. Around 2 tbsp depending on the size of the banana leaf used.
Now fold the banana leaf carefully so that the mixture won’t spill over. Bring the shorter sides to the middle and then bring each end to the middle in turn. Fold the flaps outwards so the parcel is secured.
Steam the parcel for 15 minutes, turn off the heat and rest without opening lid for half hour. Let the parcel to cool down for about 10 minutes before serving so that the otak-otak will firm up.