Add the garlic and ginger to a food processor and blitz until you have small pieces, scrap out into a large mixing bowl.
Add about 1 ½ pounds of shrimp to the bowl of the food processor and pulse a few times until you have little pieces but not a paste, scrape out into the mixing bowl.
Chop the remaining ½ pound of shrimp into small pieces, I cut each shrimp into 4 or 5 pieces, add these to the mixing bowl.
Add the remaining ingredients into the mixing bowl and mix together with your hands until you have a well homogenized mixture. This is where I always cook a small amount of the mixture to test the seasonings and adjust as needed.
Shape the meat mixture into patties. If you have a scale weigh out the meat between 4 and 6 oz or just shape it by hand trying to make the patties even. I use a lid covered in cling film to help shape my patties and make them uniform, before I remove them from the mold I press my thumb into the center and make a small divot, this helps prevent the burgers from puffing up and turning into a hokey puck.
Chill the burgers on a tray lined with cling film while you make the sweet and sour mayo and you preheat your grill.
Sweet and sour mayo
In a small pan sauté the ginger until fragrant, about 1 minutes, add in the remaining ingredients except the mayo and cook for a few minutes, stirring occasionally until the mixture thickens.
Transfer the thick chili sauce to a bowl and allow to cool before adding the mayo and stirring to combine.
Grill or pan fry the burgers until they are cooked or an internal temperature reaches 160F.
Assemble the burger on a brioche bun with butter lettuce and plenty of sauce.