As summer draws to a close there is an array of gorgeous seasonal produce such as blackberries and apples. It’s also the perfect time of year to enjoy onions, as this delicious vegetable is at its freshest and best tasting.

Olive oil specialist Filippo Berio has produced the following mouth-watering recipe which incorporates onions and is ideal as either a snack, starter or as part of a main.

Red Onion Tart

Serves 6-8
Preparation time: 25 minutes
Cooking time: 50 minutes

Pastry:

175g (6oz) plain flour
pinch salt
40g (1½oz) butter
40g (1½oz) white vegetable fat

Filling:

500g (1lb 2oz) red onions
1 tbsp lemon juice
4 tbsp Filippo Berio Mild and Light Olive Oil
2 tsp fresh rosemary spikes, chopped
75g (3oz) black olives, pitted and roughly chopped
3 medium eggs
284 ml carton single cream
Salt and pepper
50g (2oz) Gruyere cheese, grated

Method:

1. To make the pastry, put the flour and salt into a bowl, add the fats and rub in to make a fine crumb texture. Add 3 tbsp cold water and mix with a flat bladed knife until the mixture forms a dough. Gather up and knead lightly until smooth on a lightly floured work-surface.

2. Roll out, keeping a nice round shape, to line a 23cm (9”) diameter metal quiche tin, pricking the base with a fork. Place in the refrigerator for 30 minutes.

3. Meanwhile, peel the onions and slice into thin wedges, then place into a large bowl. Add the lemon juice and toss together. Heat the oven to 200°C/Fan 180°C/400°F or Gas Mark 6.

4. Heat the olive oil in a large frying pan, add the onions and fry very gently for 15 minutes or until softened, stir in the rosemary and allow to cool.

5. Line the pastry case with greaseproof paper and fill with baking beans, then bake for 10 minutes until beginning to colour around the edge. Remove the paper and beans and bake for a further 5 minutes. Remove from the oven and reduce the temperature to 180°C/Fan 160°C/350°F/Gas Mark 4.

6. Place half of the onions into the flan case and spread evenly then scatter over half of the olives and half of the cheese.

7.Beat the eggs with the cream, and season. Pour three quarters over the onions then top with the rest of the onions, remaining egg mixture, olives and cheese. Bake for about 20 minutes, or until lightly golden.