Cuts stalks off chillies (you might have to slice them in half depending on how good your blender is!).
Place chillies, passata, onion and garlic into a blender or food processor. Puree till completely smooth. Transfer to a large saucepan.
To the saucepan, add lemon juice, vinegar, water and seasonings. Stir well and bring to the boil. Lower heat to a simmer and cook for 25 minutes, stirring occasionally.
Remove from heat and let cool. Place in fridge to cool completely, about an hour. Decant sauce into container of your choice (I used glass bottles).
Serve as you wish. This hot sauce makes a great addition to chilli con carne. Recipe will give you around eight 75ml bottles. Of course adjust the chillies or the content of the liquid for different heat and quantities.