For sweet and sour butter:Mix all the ingredients together with the exception of the butter to make a vinaigrette.
Take 2 ounces of the vinaigrette and heat it with the 2 tablespoons of butter.
For crab:Char the crab legs on the plancha with 2 tablespoons of butter.
Season with sea salt and fresh pepper.
Pour the sweet and sour butter over the finished crab legs on the plate.
Top with garlic chips and sesame seeds.