Rinse 2 cups of rice until the water runs clear. Cook it in a rice cooker with 1½ cups of water, ½ cup of coconut milk, 1 teaspoon of salt, and 3 knotted pandan leaves, then discard the leaves.
Pound 4 shallots, 1 garlic clove, 8 seeded dried red chilies, and 1 teaspoon of belacan to a fine paste. Soak 1 piece of tamarind pulp the size of a small ping-pong ball in 1 cup of water, then squeeze and strain.
Heat 2 cups of oil in a wok and fry 1 cup of dried anchovies until light brown and crisp; drain. Fry 3 small cleaned mackerel in the same oil until golden and cooked through.
Pour off all but 2 tablespoons of the oil. Stir-fry the paste over medium-low heat until fragrant and reddish. Add 1 red onion, cut into rings, and the anchovies.
Stir in the tamarind juice, 2 tablespoons of sugar, and salt to taste. Simmer until the sambal thickens.
Serve the rice with the sambal, fish, 2 hard-boiled eggs, 1 cup of roasted peanuts, and 1 small sliced cucumber.
