Heat 2 tsp of oil in a wok. Add 1 tsp of mustard (optional). After it splutters, add green chillies and fry them. Add the corn and stir well on high. Let the water dry up (frozen kernels have some amount of water in them)
Add coconut and lime juice, and mix well.
Garnish with cilantro and serve. Goes well with masala peanuts and red wine.