In a small bowl, stir cornstarch with 2 tablespoons of water; set aside.
Wash crab pieces carefully with a brush to remove sand and dirt. Rinse twice and pat dry with absorbent papers. Set aside.
In a large wok, heat oil over medium heat until hot. Stir in shallots, ginger, garlic, onions, and chilies. Cook until fragrant, stirring, about 1 minute.
Add crab pieces and chicken broth, stir in tomato paste and chilli sauce. Increase heat to medium-high and bring to a boil. Cover loosely and gently boil until the crab has turned red and is nearly cooked through about 6 minutes.
Remove cover and season to taste with salt, sugar, or pepper. Stir in corn starch mixture to thicken the sauce.
Break eggs into the wok and streak with a fork. Simmer till cooked. Squeeze lime juice over.
Ladle into a serving dish, sprinkle with Chinese parsley, and serve with rice or buns.
To make deep-fried buns:
In a deep pan, add enough oil for deep frying. Until the temperature of the oil reaches 180°C, slowly slide the steam buns into the pan.
Cook until golden brown, approximately 3-4 minutes. Turn the buns to evenly golden the surfaces.
Remove the oil and sit on a paper towel to absorb excess oil.
Notes
Tips:
Ensure crabs need to be rinsed well, cleaned, and cut into pieces and possibly, get fresh crabs rather than frozen. The texture is far different from fresh and frozen.
If you are not confident with cutting up a crab, I suggest you get the fish shop to do it for you. It’s not easy at all.
I quite like to use the hot-sweet chilli sauce just because I like the taste of sweetness. If you prefer chilli hot, omit this and replace it with tomato paste and extra chilli.
If you prefer to use soft-shell crabs instead of fresh mud crabs, cut the soft-shell crab into 4 pieces and cover them with plain flour. Deep fry in hot oil and add to the sauce in step 5. After the sauce thickens, omit the mud crab.
If you like, king crabs are even better, with a lot more fresh meat, but they are more expensive.