Requiring few ingredients this recipe is surprisingly easy and really makes the most of one of Britain’s sidelined vegetables

Serves 4 




300g puff pastry, thawed if frozen

75g butter

500–600g mixture of small to

medium sized onions and shallots

1-2 tbsp balsamic vinegar

Salt and pepper

75g crumbled Caerphilly cheese












  1. Heat the oven to 200˚C.
  2. Peel the onions and shallots.  Slice the onions in half from root to tip.
  3. Melt the butter in a 23-25cm heavy non-stick tin or frying pan which can be placed in the oven.
  4. Place the onions cut side down and the shallots in the butter – they should fit snugly.  Cook over a low heat for 15-20 minutes until the underside is golden and they yield to the point of a knife.
  5. Carefully turn the onions and shallots, season and make sure they are evenly spread over the tin/pan and continue cooking until the onions and shallots are completely soft.
  6. Sprinkle with the balsamic vinegar and cook for a further 2 minutes until the vinegar starts to reduce.
  7. Remove the onions and shallots from the heat allowing them to cool for 15-20 minutes.
  8. Roll out the pastry to a diameter roughly 2cm larger than the tin/pan.  Lay it over the shallots and onions and then tuck the pastry around the sides of the tin/pan.
  9. Bake for 20-30 minutes until the pastry is well puffed and golden.  Remove from the oven and allow to cool slightly.
  10.  To remove the tarte from the tin place a large serving plate over the top of the tin/pan.  Quickly and firmly turn the tin/pan and give it a little shake if necessary.  If the onions are stuck to the bottom of the tin/pan use a palette knife to carefully remove them.
  11.  Scatter the tarte with the cheese before serving.