Peel and thinly slice the shallots and garlic.

Heat the cooking oil in the wok over medium heat.

Fry the dried anchovies in the hot oil until golden and crisp, about 3 to 5 minutes.

Remove the crispy dried anchovies from the wok and set them aside.

Add the sliced shallots and garlic to the remaining oil, then sauté until lightly golden.

Stir in the blended chili paste and fry it over medium-low heat until fragrant and the oil begins to separate.

Add half of the water and cook the sambal until it thickens and becomes glossy.

Add the remaining water and fry again until the sambal is reduced, repeating this drying process 2 to 3 times in total.

Season the thick sambal with sugar, salt, and tamarind paste.

Add the petai beans and stir until they are coated in sambal and warmed through, about 3 to 5 minutes.

Turn off the heat and let the sambal cool slightly to preserve the anchovies' crisp texture.

Fold the fried dried anchovies into the cooled sambal, then serve immediately.