Boil the vegetables separately in slightly salted water, for 3-4 minutes, except the beansprouts which only need 2 minutes. Drain each vegetable separately in a colander.
To serve, arrange the lettuce and watercress around the edge of a serving dish. Then pile the vegetables in the middle of the dish. Arrange the eggs, sliced potatoes or lontong, and sliced cucumber on top.
Heat the peanut sauce in a small saucepan until hot; add more water if it is too thick. Adjust the seasoning, and pour the sauce over the vegetables. Sprinkle the fried onions on top. Serve warm or cold. If you want to serve hot gado-gado, it can be reheated in a microwave oven. When reheating, however, do not include the lettuce and watercress, cucumber slices, fried onions, krupuk or emping. Add these garnishes immediately before serving.
1/2 cup vegetable oil
1-1/3 cups raw peanuts
2 cloves garlic chopped
4 shallots, chopped
thin slice of shrimp paste (optional)
salt to taste
1/2 tsp chilli powder
1/2 tsp brown sugar
1 tbsp dark soy sauce
2 cups water
1 tbsp tamarind water or juice of a lemon
Stir-fry the peanuts for 4 minutes. Remove with a slotted spoon to drain in a colander, and leave to cool. Then pound or grind the nuts into a fine powder, using a blender, coffee grinder, or pestle and mortar. Discard the oil, except for 1 tablespoonful.
Crush the garlic, shallots and shrimp paste in a mortar with a little salt, and fry in the remaining oil for 1 minute. Add the chilli powder, sugar, soy sauce and water. Bring this to the boil, then add the ground peanuts. Simmer, stirring occasionally, until the sauce becomes thick; this should take about 8-10 minutes. Add the tamarind water or lemon juice and more salt if needed.
When cool, keep in a jar in the fridge. Reheat as required for use with satay or as a dip for lalab (crudites) or savoury snacks. The sauce will keep in the fridge for up to 1 week.