Requiring few ingredients this recipe is surprisingly easy and really makes the most of one of Britain’s sidelined vegetables
300g puff pastry, thawed if frozen
500–600g mixture of small to
medium sized onions and shallots
1-2 tbsp balsamic vinegar
Salt and pepper
75g crumbled Caerphilly cheese
- Heat the oven to 200˚C.
- Peel the onions and shallots. Slice the onions in half from root to tip.
- Melt the butter in a 23-25cm heavy non-stick tin or frying pan which can be placed in the oven.
- 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.
- 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.
- Sprinkle with the balsamic vinegar and cook for a further 2 minutes until the vinegar starts to reduce.
- Remove the onions and shallots from the heat allowing them to cool for 15-20 minutes.
- 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.
- Bake for 20-30 minutes until the pastry is well puffed and golden. Remove from the oven and allow to cool slightly.
- 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.
- Scatter the tarte with the cheese before serving.