If you are using a clay pot, soak it in water for at least an hour before using it; or you can use an ice bain-marie by placing the mixing container in a larger bowl filled with ice.
Prepare the banana leaf wraps or containers:
Lightly pass fresh banana leaves over an open fire until they soften.
If you are making your own coconut cream, grate and squeeze thick coconut cream with no or just a little water added. If you order fresh coconut cream at the market, ask for a cream squeeze without water added.
Reserve half a cup of coconut cream for the topping. Place it in a pot, add a pinch of salt and bring it to a gentle boil over low heat. Allow it to thicken slightly and do not let it separate. Set aside and let it cool.
Prepare the proteins:
Cut the chicken fillet into very thin slices; wash and set aside.
Cut the pork into very thin slices; wash and set aside.
Cook the crab and collect the meat, or use pre-cooked crab meat, which is readily available in Thai markets. If fresh crab is not available, use pasteurized crab meat.
Prepare the paste:
De-seed and rehydrate the dried chilies in hot water. Pound the curry paste; start with the chilies and salt, and gradually add the other ingredients, from the driest to the wet. Pound the paste until it is smooth with a rounded aroma.
For textural and visual considerations, pound the paste to the finest consistency possible.
Emulsion-stirring (กวนห่อหมก):
Add the meats to the mixing bowl. Add salt to facilitate thickening the mixture.
Start adding coconut cream. Start with an amount equal to half the volume of the protein and gradually add more as you stir the mixture.
Using a wooden paddle (traditional) or a silicone spatula, gently stir the meat and the coconut cream in one direction only. Gentle stirring is essential for emulsifying the proteins, fats, and liquids without the risk of the mixture breaking, separating, overheating, or forming foam – all of which will adversely affect the dish's texture. Keep stirring while gradually adding more coconut cream as the mixture thickens and becomes smooth.
When the meats and coconut cream have blended into a smooth consistency, add the paste. Continue stirring, maintaining the same pace and mixing direction.
Season to a salty leading with a sweet floor flavor profile. Start by seasoning the salty element using fish sauce.
When you are satisfied with the saltiness, add granulated sugar to adjust the natural sweetness of the coconut cream.
If necessary, adjust spiciness with ground dried chili.
Add the duck egg and continue the process of emulsion-stirring, maintaining the same pace and mixing direction, until the proteins, coconut cream, paste and the egg have incorporated into a thick and very smooth consistency.
The entire mixing process takes about 45-60 minutes to complete. Mixing it thoroughly and gently, as described above, is crucial to achieving the desired texture of the steamed curry.
Check the seasoning by grilling a small portion of the mixture in banana leaves and adjust accordingly.
Steaming:
Line the banana leaf with Thai basil, then scoop out a bite-size portion of the mixture and place it on top of the Thai basil.
Garnish with coriander leaves and thinly sliced spring onion and drizzle the thick coconut cream on top.
Wrap the haaw mohk and place it the steamer. Repeat until all the mixture is processed.
Steam over moderate heat for 8-10 minutes. Do not use high heat – if you do, the haaw mohk mixture will overly inflate and become soggy.
Serve it in the banana leaf wrap or remove and serve on a plate. Garnish with fresh spring onions and coriander leaves.