Heat ghee or oil in a kadhai or wide pan over medium flame. Add mustard seeds and let them crackle for 10 seconds.
Add cumin seeds and asafoetida. Stir for 5 seconds until fragrant.
Add ginger paste and slit green chilies. Saute for 30 seconds until the raw smell disappears.
Add chopped tomatoes, turmeric powder, coriander powder, red chili powder, and salt. Mix well to coat the tomatoes with spices.
Cook on medium flame for 8 to 10 minutes, stirring occasionally, until the tomatoes soften completely and the oil starts separating from the masala. Mash the tomatoes lightly with the back of your spoon if needed.
Add grated jaggery and crushed kasuri methi. Stir and cook for another minute to let the jaggery dissolve.
Add half the sev (about half a cup) into the gravy and mix gently. Pour in 1/4 cup water if the consistency is too thick. Simmer for 2 minutes.
Turn off the heat. Top the sabzi with the remaining sev and fresh coriander leaves. Serve hot immediately.
Notes
Tomatoes - Choose soft, juicy tomatoes. Firm ones take longer to cook and may lack flavor. You can substitute with 1 cup canned crushed tomatoes.
Sev storage - Keep extra sev in an airtight container. It stays crispy for weeks and works well in chaats or as a snack.
Make ahead - You can prepare the tomato base up to step 6 and refrigerate for a day. Reheat, add sev, and serve fresh.
Spice level - Adjust green chilies and red chili powder based on your tolerance. Start with less and add more if needed.
Equipment - A wide kadhai helps the tomatoes cook faster by allowing moisture to evaporate quickly.
Vegan option - Use oil instead of ghee. The dish remains flavorful and completely plant based.
Serving fresh - This sabzi tastes best when served immediately after adding sev. Reheated sev loses its crunch.