Firstly, boil the water in a pan on medium heat and add chopped onion, tomatoes, dried red chili, and let them cook for about 4-5 minutes. Switch off the flame.
After that, cover the pan with a lid and keep them aside for 5 minutes.
Then, remove the lid and carefully drain the water using a strainer and allow them to cool down for a few minutes.
Further, in a blender or food processor, add chopped ginger and boiled veggies.
Blend all the ingredients together until you achieve a smooth and well-combined chutney consistency. You can adjust the consistency by adding a little water if needed.
Now, heat oil in a wok/kadai on medium flame and add finely chopped garlic and saute for a few seconds or until the raw smell of garlic goes off.
Additionally, add tomato onion chilli paste and mix well.
Now add Sugar, Salt, and Vinegar and boil on high flame for 5-7 minutes.
Make sure to stir occasionally, to prevent it from burning.
Taste the chutney and adjust the seasoning according to your preference. Add more salt or vinegar if desired.
Cook the mixture till the water from the sauce is evaporated completely, and the chilli chutney turns thick.
Once the chilli sauce for momos reaches the desired taste and consistency, keep it aside for cooling down completely.
Finally, transfer the momos sauce to a serving bowl.
Your delicious Momos Chutney is now ready to be enjoyed! Serve it alongside steamed or fried momos as a dipping sauce or drizzle it over the momos/dumplings for an extra burst of flavor.