|Plain flour||12 Ounce (350 Gram)|
|Cold butter||8 1⁄2 Ounce, chopped into small chunks (225 Gram)|
|Butter||4 Ounce (100 Gram)|
|White wine vinegar||2 1⁄2 Fluid Ounce (75 Milliliter)|
|Soft light brown sugar||1 1⁄2 Tablespoon|
|Dijon mustard||1⁄2 Teaspoon|
|Maldon salt||2 Teaspoon|
|Parmesan||2 Ounce, freshly grated (50 Gram)|
1) Pastry : In a food processor, process the flour with the butter until the mixture has fine crumbs.
2) Gradually add the egg yolks until combined.
3) Bring the mixture together with hands on the work surface.
4) Wrap in cling film and allow to rest in the refrigerator for 2 hours.
5) Peel and finely dice the onions.
6) Preheat the oven to 200°C/fan 180°C/gas mark 6.
7) Grease a 27cm tart tin.
8) In a large pan, melt the butter over a medium heat.
9) Cover and saute the onions over a low heat for about 2 hours, stirring occasionally.
10) When the onions are verysoft, add the vinegar, sugar, mustard and the salt.
11) Cook for about 30 minutes until the vinegar evaporates fully and the onion begins to caramelise, stirring occasionally. Keep the onion mixture aside.
12) On a lightly floured surface, roll out the pastry and place in the tart tin with the pastry overhanging the sides of the tart tin.
13) Cover the pastry with foil and add the baking beans.
14) Bake in the preheated oven for 25 to 30 minutes, until evenly golden.
15) Then uncover and bake for another 5 minutes.
16) Allow the pastry to cool, then gently trim off the overhanging pastry. 17) Spoon in the onion mixture and smooth it out evenly with a spatula. 18) Sprinkle with the grated Parmesan and a grind of pepper.
19) Return to the oven for a final 10 minutes.
20) Slice and serve the Onion Tart with a few salad leaves on the side.