Heat the oil in a pan over a medium heat and fry the onion for 5 mins. Add the garlic and cook for 5 mins more until the onion is soft but not golden. Remove from the heat and leave to cool.

Bring a large pan of salted water to the boil and cook the asparagus for 3 mins. Drain, then plunge into a bowl of cold water to stop the cooking process. Drain again. Set eight spears aside, then chop the rest into 3cm lengths.

For the pastry, combine the flour and cheese in a bowl, then rub in the butter using your fingers until the mixture resembles breadcrumbs. Add 1 tbsp cold water at a time until the mixture comes together into a dough – you may need 3-6 tbsp water. Wrap and chill in the freezer for 5 mins to firm up slightly.

Roll the pastry out on a lightly floured surface until it’s large enough to line a deep 23cm flan tin with a slight overlap. Using the rolling pin to help you, unravel the pastry over the tin and gently push the pastry into the edge. Trim the overhanging pastry so it comes up 2cm past the rim of the tin. Gently prick the pastry base all over using a fork, then return to the freezer to chill for 15 mins. Heat the oven to 200C/180C fan/gas 6.

Scrunch up a square of baking parchment, then use it to line the chilled pastry case. Fill with baking beans and bake for 15 mins. Remove the baking beans and parchment and bake for 5 mins more. Leave to cool. Meanwhile, combine the cream, crème fraîche, yogurt and eggs in a bowl, but don’t stir too hard – avoid creating bubbles. Stir in the fried onion mixture, the pepper and paprika, then fold in the dill, most of the feta and the cooked asparagus.

Put the pastry case on a baking tray. Pour in the filling, ensuring the feta and chopped asparagus are evenly distributed, then add the whole asparagus spears and remaining feta.

Put in the oven and immediately reduce the temperature to 180C/160C fan/gas 4. Bake for 35-40 mins until set with a slight wobble in the middle. Leave to cool before slicing.