Clean shrimp, season with ginger and salt and leave to marinate for 10 minutes.
Heat a wok and fry shrimp in batches to ensure that you are not overcrowding the pan and for about 2 minutes.
Set shrimp aside to drain and preheat another pan with a drizzle of olive oil.
Toss lemongrass stalk in oil and let fry for 2 minutes over medium heat and remove.
Fry garlic until they are just about turning brown and set aside.
Stir-fry green, red, and yellow peppers with shallots for a few minutes.
Add garlic back into the pan and then add spring onions.
Add fried shrimp to pan and mix thoroughly for a maximum of 1 minute.
Turn off heat and serve hot or warm.