Prepare the ingredients: Wash the red chillies, remove their stems, and roughly chop them. Peel and chop the garlic cloves.
Blend the mixture: Add the red chillies, garlic, vinegar, and salt to a blender. Blend into a slightly coarse paste.
Cook the sauce: Transfer the mixture to a saucepan and cook over low heat for 5–8 minutes, stirring occasionally.
Adjust the consistency: If the sauce is too thick, add a little water and simmer until it reaches your preferred consistency.
Cool and store: Allow the sauce to cool completely. Transfer it to a clean, airtight jar and refrigerate.