1.Heat oil in medium saucepan. Cook onion, beetroot and chilli, for 45 minutes with lid on pan. Stir occasionally, until vegetables soften.
2.Remove lid and add vinegar and sugar. Continue stirring and cook without lid for about 20 minutes or until jam is thick. Remove from heat and stir in mint and salt.
3.Spoon hot jam into hot sterilised jars; seal immediately. Label and date jars when cold.