Gently rinse the shrimp and pat dry. Remove the heads and peel the shell so that the tail tips remain. Remove the intestines with a knife.
Rinse the scallions and chop finely. Separate the garlic and finely chop. Halve and rinse the chile peppers, remove the seeds and finely chop. Rinse 1 lemon and grate the zest. Squeeze the juice from both lemons.
For the marinade, mix the lemon juice and zest with the garlic, scallions, chile peppers, vinegar, oil, mustard, cornstarch, curry powder and sugar and marinate the shrimp at room temperature for 30 minutes.
Peel the pineapple from the leaf to the stalk neck and cut into 1 cm thick slices (approximately 1/2 inch). Cut out the solid stalk and chop the flesh into about 1 x 1 cm pieces (approximately 1/2 x 1/2 inch).
Drain the shrimp, season with salt and thread alternately onto skewers along with the pineapple chunks.
Cook on all sides on the grill over high heat for 2-3 minutes, brushing regularly with the marinade.