Heat up pan or wok under medium fire, and add cooking oil. Saute garlic and chopped onion, for about 30 seconds. Add chopped tomatoes, and add a pinch of salt. Let it cook until juice from tomatoes come out. It’s important that you cook the tomatoes properly to avoid food spoilage, and to slightly remove the tangy flavor.
Add the shrimps and ginger paste, turn heat up into medium high. Add butter, sweet chili, water, lemon juice, salt, ground black pepper, and sesame oil. Saute and mix well for a minute.
Add chopped white part of the spring onions and let it cook for another 30 seconds.
Add the green part of the spring onions, and mix it well for another 30 seconds, until it’s slightly cooked. Do not overcook the spring onions.
Sprinkle as many chili flakes as you like, or even fresh chilis! Mix for another 10 to 15 seconds. Taste before serving, and adjust taste to your liking if necessary.
Turn off the heat, and transfer the shrimps to a serving dish.