Slice red onions thinly.

Peel and chop apples into small cubes.

Chop garlic finely.

Place onions, garlic, and brown sugar in a heavy-bottomed pan.

Cover and cook on medium heat until onions are soft (about 10 minutes), being careful not to burn the sugar.

Add apples and cook for another 5 minutes.

Pour in red wine and red wine vinegar.

Add salt.

Cook without the lid at a gentle simmer until the mixture has reduced, thickened, become sticky, and the apples have softened.

Remove from heat.

Add pomegranate concentrate and stir through.

Allow to cool completely.

Store in sealed, sterilized glass jars.