In a deep skillet or kadai, heat oil on medium-low flame.
Once the oil is hot, add mustard, cumin and let the mustard pop and cumin sizzle.
Now add red chillies, curry leaves, asafoetida and stir and fry for few seconds.
Add tomato puree followed by turmeric, chilli powder, coriander powder, cumin powder, salt and mix until well combined.
Increase the flame slightly and cook for 2-3 minutes.
Now add chopped kohlrabi, water and mix until it is well coated with tomato masala. Close the kadai with a lid.
Reduce the heat to lowest possible setting and cook for around 10 minutes.
Take off the lid, add desiccated coconut, crushed peanuts, coriander, lemon juice, mix well and turn off the heat.
Serve piping hot kohlrabi curry with roti or rice.