Clean the crab, scrub the shell, cut into serving pieces, and boil in vigorously boiling water for 10 minutes, until the shell turns orange, then drain.
1 whole crab
In a bowl, beat the eggs with the light soy sauce, sugar, the yellow curry powder, white pepper, and roasted chili paste (nam prik pao) until smooth, then set aside.
Heat the oil in a wok over medium heat. Add the remaining yellow curry powder and stir-fry until fragrant, then gradually stir in the powdered milk to bloom the flavors.
Increase heat to high. Pour in the egg-curry mixture and stir until it thickens into a creamy sauce, then add the boiled crab pieces and toss to coat.
Add the onion, Chinese celery, scallions, and red chiles; stir just until the vegetables are glossy but still crisp. Serve immediately with jasmine rice.
0.5 onion, 2 stalks Chinese celery (kunchai), 3 stalks scallions, 2 small Thai red chiles
Notes
Powdered milk combined with eggs creates the silky, custardy sauce that sets this dish apart from Indian or Malaysian crab curries.
A splash of Shaoxing wine adds extra aroma, but it's optional for home cooking.