With a food processor: combine all patty ingredients and pulse until sticky but still slightly chunky. Without a food processor: mince garlic and shallot, grate ginger into a bowl, crush cornflakes in a bag, dice salmon finely by hand, add remaining ingredients and mash together.
Form the mixture into patties.
Heat a skillet on medium with avocado or olive oil. Sear patties 3–4 minutes per side until browned, then transfer to the oven for approximately 15 minutes.
While the patties cook, whisk all sauce ingredients together.
Spread sauce on a bun, add the patties with tomato, cucumber, and greens. Alternatively, serve over rice or on a salad.