Let's begin with de-seeding the chilies.
Cut chili in half...
Open and remove all the seeds.
Remove seeds in a bowl...
Remove the dried membrane and discard.
All we need is the skin of red chilies. If you have a sensitive skin then these chilies may irritate your skin, make sure you wear gloves before removing seeds from these chilies.
All the red chilies are de-seeded and ready. Discard the seeds.
Transfer cleaned chilies to a mixer...
Add 1/4 cup water and grind it to a smooth paste.
Heat sesame oil in a pan, add chopped garlic, ginger and saute for 1 minute.
Mix in chopped onions and saute for for another 1-2 minutes until onions are translucent.
Pour in szechuan paste..
Add tomato ketchup...
Add soy sauce...
Pour in vinegar and bring it to a boil. Add sugar and mix until well blended.
Adjust sweetness and salt. Sezchuan sauce is ready.
When completely cooled store it in an airtight container and its good for 3-4 weeks in your refrigerator and for 6 months in your freezer.