Boil the arvi for about 30 minutes until soft.
Peel and cut into slices.
Heat oil in a pan, add chopped garlic, and fry until golden brown.
Add mustard seeds, nigella seeds, cumin seeds, and whole black peppercorns.
Add chopped tomatoes and cook until soft.
Add all spices and cook for 2 minutes.
Add boiled arvi and mix well.
Cover and cook on low flame for 5 minutes.
Garnish with fresh coriander leaves, green chillies, and lemon slices.
Squeeze fresh lemon juice while eating for the best flavor.