This particular pickle must be the simplest way of pickling limes. As opposed to sweet lemon pickle, or spicy version of it, this lemon ginger pickle makes use of green chillies as opposed to red ones. Green chillies and ginger are seasoned onto lemon pieces that are marinated in salt and fenugreek powder.
Find this recipe here: http://udupi-recipes.com/2014/02/lemon-ginger-pickle-recipe.html