Sweet Onions Tart with chicken and blue cheese

Sweet Onions Tart with Chicken and Blue Cheese 
(makes 6 portions) 

Pastry

125 g soft flour 

125 g unsalted butter

5 g salt

1 egg

15 ml cold water 

 Filling 

2 tbsp butter 

2 tbsp olive oil

3 large red onions 

3 tsp sugar 

2 previously baked chicken legs

200 ml double cream 

2 eggs 

100 g blue cheese (Saint Agur, Roquefort or any other smelly blue)

Salt, black pepper  

Preheat the oven to 180°C. Sieve flour and salt into a bowl. Cut the butter into pieces and rub into a flour until the mix resembles fine breadcrumbs. Make a hole in the middle and add beaten egg and water. Bring together to a form a dough. Rest in the fridge for 20 minutes. When ready, line large a tart tin and bake in previously preheated oven for 15 minutes, till slightly brown. 

Place a large pan over medium heat and melt the butter and olive oil. If you wondering, why combining those 2 fats answer is simple: butter adds a lot of flavor to your dish, but it burns in low temperatures. By mixing those two, you simply end up with blend full of flavor, which allows you to fry on higher temperatures without burning your dish.

Chop onions thinly and add to the pan. Stir them, to make sure they all coated with fat. 

Fry for around 15 minutes, checking from time to time. If you think they are still quite hard, add some water, and leave it for another 10 minutes, till becomes soft. Add sugar, some salt and pepper for flavor and  keep on the heat for another 5 minutes till sugar melts. When ready, leave it on the side to cool a little. 

Scrape meat off the chicken leg. Spread the onions and chicken meat over previously baked pastry, and crumble half of the cheese on the top. In a small bowl mix double cream and egg, add salt and pepper. Pour over the top, and scatter over rest of the blue cheese. Bake until set and nicely colored, approximately 25 minutes. Serve warm or cold.