The Shortcrust Pastry:

225g (8oz) plain flour
150g (5oz) butter
1 egg plus a teaspoon of cold water

The Filling:

4 medium onions
½ tablespoon balsamic vinegar
1 tablespoon olive oil
1 clove of garlic (optional)
Salt and freshly ground black pepper

  • Makes 24
  • You will need 2 mini muffin tart tins
  • Any mixture leftover can be frozen.


  1. Preheat the oven to 200C (400F, Gas mark 6).
  2. Peel and chop the onions as finely as possible and crush the garlic if using.
  3. Heat the oil in a large pan then tip in the onions.
  4. Add the garlic and season with salt and pepper.
  5. The cooking of the onions is crucial. First, it should fry to give it some colour, then cook slowly with a lid on so the onions become very soft.  Finally, increase the heat and remove the lid to reduce the liquid and cook it to an almost jam-like consistency.
  6. Towards the end of the cooking add the balsamic vinegar.
  7. Allow the mixture to cool.
  8. Line the tins with the pastry and fill with the onion mixture, three quarters full.
  9. Bake in the oven for about 15 – 20 minutes or until cooked.