Makes about 80
2 to 3 thick stalks lemongrass
2 pounds shallots
2 ounces blue ginger or galangal
2 ounces yellow ginger or turmeric
2 tablespoons toasted, crumbled belacan
2 ounces candlenuts (macadamia nuts can be substituted)
3 ½ ounces dried chilies, boiled in hot water for 15 minutes to soften
12 chili padi, also known as bird’s-eye chilies (add more if you want it to be spicier)
¾ tablespoon plus ¾ teaspoon salt
1 ¼ cups vegetable or canola oil
Fresh banana leaves,* cut into 8-inch-by-5-inch rectangles
2 pounds mackerel
3 ½ cups coconut milk
8 eggs, beaten
1 ½ tablespoons sugar
2 tablespoons ground coriander
2 tablespoons tapioca flour
¼ teaspoon monosodium glutamate
*Note: If you can’t find fresh banana leaves, you can scoop the fish paste into a bowl and steam it.
Thinly slice the lemongrass, shallots, blue ginger or galangal, and yellow ginger or turmeric, and blend them together in a food processor with the crumbled belacan, candlenuts, and a little water. Remove the paste, transfer it to a large wok, and fry over medium heat.
Blend together the softened dried chilies and chili padi in the food processor with about ¼ cup of water. Add the chili mixture to the paste in the wok. Add ¾ tablespoon of salt.
Keep frying the paste. After 30 minutes, start gradually adding about 1 ¼ cups of oil to the mixture while frying. You want the mixture to get really dry. The best way to tell whether there’s still water in the paste is to add oil by the ¼ cup and then inspect to see if white wispy strands appear. If you see the wisps, there’s still water in the mixture.
After about 90 minutes, the paste should be dry enough. Remove it from the wok and let it cool overnight.
The next day, fill a large wok with water and bring it to a boil. Soak the banana leaf rectangles in batches in the water for 1 or 2 minutes to soften the leaves. You want them to be pliant enough to be folded with ease.
Cut the fish into smaller-than-bite-size pieces. In a large mixing bowl, whisk together 4 to 5 cups of the chili paste (add more if you like it spicy), the coconut milk, eggs, sugar, coriander, tapioca flour, monosodium glutamate, and ¾ teaspoon of salt. Add the fish to the bowl and mix well.
Take a banana leaf, position it on your hand so its veins are vertical, then scoop 2 to 3 tablespoons of the fish mixture onto the leaf so it forms a slender vertical strip along the middle. Make sure the paste does not reach the ends of the leaf; you don’t want it to spill out.
Fold over the left side and then the right side of the leaf so you have a long, slender otah that’s about 1 ½ inches wide. Secure the top and bottom with sharp toothpicks. Repeat with the rest of the mixture.
Steam the otah for 10 minutes and serve them with rice or bread.