Place the dried shrimps in a shallow bowl and pour in just enough hot water to cover. Leave to rehydrate while you prepare the rest of the ingredients.
Cut off any tough spinach stalks and discard. Rinse the spinach well and drain. Roughly chop.
Halve then thinly slice the onion.
Peel and mince the garlic.
Roughly chop the rehydrated shrimps (if the amount of water you used to rehydrate them is correct, there shouldn't be any liquid left in the bowl).
Heat the cooking oil in a wok or frying pan.
Saute the sliced onion, minced garlic, ginger powder and rehydrated shrimps for about half a minute.
Turn up the heat to high. Add the spinach to the pan. Pour in the soy sauce, oyster sauce and sprinkle in the sugar. Cook until the spinach wilts and the liquid in the pan has been reduced to half.
Taste the sauce. If needed, sprinkle in salt (adding more soy sauce at this point will make the dish look too dark).
Serve the sautéed spinach with dried shrimps with your meat dish. It's also great as a light main dish.