Passata, tabasco, mint sauce.......think that is generally what is in a kebab sauce.....I am sure my local has a touch of cinnamon in it too. Play about with quantities to get the taste you want. Someone else might have a more specific recipe for you.
I take a cartoon of chopped tomatos, add finely chopped onion, chopped chilli, garlic, dash of tabasco, dash of Worcestershire sauce and a little powered chilli. Amounts are to taste and depending if im serving it up to anyone else as I like my chilli sauce hot