Peel prawns, except for the tail fins. Cut into the back and remove the dark gut. Rinse shrimps and pat dry.
Clean, wash and chop the spring onion. Carve the chilli lengthwise, remove seeds, wash, dab dry and chop finely. Peel 1 clove of garlic and ginger, also chop.
For the sauce, dissolve tamarind pulp in 150 ml hot water, then pass through a sieve. Mix with 50 ml fish sauce, 50 g sugar and half the chilli.
Sort the spinach, wash well and drain. Peel the rest of the garlic and cut into fine slices. Heat 1 tsp. oil in a frying pan. Fry the garlic slices and spinach for about 2 minutes.
Stir in the oyster sauce, 2 teaspoons of fish sauce and 1 pinch of sugar and cook over medium heat for about 4 minutes.
In the meantime heat 1 teaspoon of oil in a second pan. Sauté the spring onion, the rest of the chilli, chopped garlic and ginger over medium heat. Add the prawns and fry them for about 2 minutes, turning them over.
Add tamarind sauce to the prawns and simmer for 2-3 minutes.
Arrange spinach with prawns on plates. Sprinkle with fried onions. Basmati rice tastes good with it.