Wash the ridge gourd under running water, slice off the ends, and cut into 1‑cm cubes. Pat dry with a clean kitchen towel to prevent splatter when added to hot oil. (Safety: Keep fingers away from the pan edge.)

Finely chop the onion and tomato. Measure all spices and keep them within arm’s reach for a smooth cooking flow.

Place a heavy‑bottomed kadhai or deep skillet on medium heat. Add 2 tbsp mustard oil and let it warm until it shimmers. (Safety: Use a pot holder; oil can become very hot.)

Add 1 tsp cumin seeds and ½ tsp mustard seeds. When they start to crackle, swirl the pan gently to coat the seeds evenly.

Sprinkle ¼ tsp asafoetida (hing) and stir quickly; it releases a savory aroma that balances the gourd’s mildness.

Add the finely chopped onion to the pan. Stir continuously for 2–3 minutes until the onion turns translucent and begins to turn golden at the edges. This develops a sweet base flavour.

Stir in 1 tsp ginger‑garlic paste. Cook for another 30 seconds, watching for a fragrant sizzle. (Safety: Avoid splatter; keep a lid nearby.)

Add the chopped tomato and cook for 3–4 minutes until the tomato softens and the oil starts to separate from the mixture.

Sprinkle ½ tsp turmeric powder, 1 tsp coriander powder, and ½ tsp red chilli powder over the onion‑tomato mixture. Stir quickly for 1 minute to toast the spices, which deepens their flavour without burning them.

Add a pinch of salt (about ¼ tsp) to help the tomatoes break down faster.

If you prefer a slightly thicker gravy, mix 1 tbsp roasted besan with 2 tbsp water to form a smooth slurry. Stir the slurry into the simmering sabji and cook uncovered for another 2 minutes. This step is optional and adds body without refined flour.

Taste the sabji and adjust salt as needed. Add 1 tsp lemon juice to brighten the flavours, stirring gently.

Turn off the heat. Garnish with 2 tbsp fresh chopped coriander leaves for a burst of colour and freshness.