The ultimate makeover: Lemon tart

Name: The ultimate makeover: Lemon tart
Prep time: 35 min
Cook time: 55 min
Total time: 1 h 30 min
Cuisine: French
Ingredients: 50g butter, cut in pieces; 140g plain flour; 1 tbsp icing sugar; 1 tbsp extra virgin rapeseed oil; 1 medium egg yolk; 3 medium eggs, plus 2 medium egg whites; 140g icing sugar, plus extra for dusting; 2 tbsp finely grated lemonzest (about 4 lemons); 125ml lemon juice(from 4-5 lemons); 200ml tub half-fat crème fraîche