Blend spice paste ingredients with ¼ cup (60ml) water. Transfer to a bowl.
Prepare the soup
Rinse asam jawa. Place in a bowl with 1 cup (240ml) hot water. Stir to dissolve some of the pulp then strain for the juice. Discard pulp.
Bring 8 cups (2 liters) water in a large pot to a boil. Add ikan kembung (mackerel), lower heat to medium low and simmer for 15 minutes. Remove fish when cooked. Strain liquid with a metal strainer. You should get about 6 cups (1.5 liters) fish stock.
Add tamarind juice, blended spice paste, asam gelugor, and daun kesum into pot with fish stock. Bring to a boil, lower heat, and allow it to simmer while you prepare the fish.
When fish is cool enough to handle, remove bones and flake the meat. Break into small pieces but keep some in bigger chunks.
Return flaked fish to the pot.
Season the soup with sugar and salt.
Cook the noodles
Cook noodles in boiling water for 1 to 2 minutes. Remove and strain.
Serve
Place some noodles in a bowl. Top with a little julienned cucumber, pineapple, onion, red chili, mint leaves, and bunga kantan (torch ginger). Pour gravy over the noodles.
Serve immediately with hei ko (shrimp paste) and lime wedges.
Notes
**If tamarind paste is not available, 1 to 2 teaspoon (depending on taste) tamarind concentrate may be used instead.
***Dried thick vermicelli should be cooked in boiling water for a minute. Then turn off heat and let it soak for 6 to 8 minutes until soften. Remove and drain before serving.