Ajvar
A Balkan paste of roasted red peppers, often with aubergine, garlic and oil, either mild or hot.
Ajvar is sold in jars in many larger supermarkets, and reliably in Balkan, Turkish or Eastern European shops. It can be replaced with roasted, peeled red peppers blended with a little oil and garlic.
Substitute:
Roasted, peeled red peppers blended with oil, garlic and a little vinegar come very close. Turkish pepper paste is denser and often saltier, so use less of it.