To prepare the curry leaf oil, place oil in a small saucepan on medium high. Add the mustard seeds. In a few seconds when they start to crackle and spit, add the chilli and curry leaves. Reduce heat to low and cook for a minute until warmed through. Remove from heat and set aside.
To prepare the fritters, place cabbage, besan, rice flour, salt, chilli, cumin, turmeric, lime juice and soda water in a large bowl. Mix well to form a thick batter.
Heat a bit of oil in a large frying pan on medium. Drop a cup of batter in the centre of the pan and flatten/spread it a bit with a spatula. Allow to cook for 4-5 minutes until the base is crispy and starting to brown around the edges. Carefully flip the fritter and cook the other side for 3-4 minutes until crispy and starting to brown. Press down on the fritter to ensure there are no wet, uncooked bits. Remove to a plate. Repeat with the remaining batter.
To serve, top the fritter with coconut yoghurt and a small dollop of mango chutney. Spoon some curry leaf oil (make sure you get chilli slices and curry leaves) on the yoghurt. Garnish with coriander.
Cabbage - The variety of cabbage is important to the fritter. You could make it with any cabbage but a drumhead cabbage will produce the best result and make it really crispy. I find that drumhead cabbage is firmer and releases less water when cooked compared to its other cabbage counterparts.
Adjusting Heat When Cooking - Whenever you are pan-frying batter, it is important to not cook it on very high heat and this can cook the outsides super quickly while retaining uncooked soggy bits in the middle. I start pan-frying fritters/pancakes on medium and then medium-low when both sides are cooked to ensure both outside and inside gets cooked.