Boil 1 cup of water in a pan . Switch off. To the hot water add red chillies and let it soak for 15 mins.
Transfer the red chillies along with water .Add salt , sugar and vinegar to it . Blend it to a puree.
In a kadai / pan heat oil . When its hot add the chilli garlic puree . Keep the flame on medium and bring it to boil . Keep th eflame on sim and boil well for about 5-10 mins so that flavors will get enhanced and also the sauce will attain a nice consistency .
Meanwhile , mix cornflour in 2 tbsp of water .
Pour this over the sauce . you will see that now sauce will start to thicken more . If you feel it became very thick , can add few tbsp of water . Give a final boil and switch off . Cool .
Serve the spicy dip with momos , spring rolls ,fritters, wontons, noodles etc . Put it in air tight container and store in fridge , use as and when required. Tastes best for few weeks if boiled well .