Preheat the oven to 180ºC/350ºF/gas 4. Tip the flours into a bowl with a good pinch of sea salt, then chop and rub in the butter. Make a well in the middle, crack in one of the eggs, add 2 tablespoons of cold water, then mix, pat and bring together. Place between two large sheets of greaseproof paper, flatten to 1.5cm thick and chill in the fridge for 30 minutes. Roll out the pastry between the sheets of greaseproof, then line a 25cm loose-bottomed tart tin with the pastry, easing and pushing it carefully into the sides and letting the pastry scruffily hang right over the sides (this will stop it shrinking). Prick the base all over with a fork and bake for 20 minutes, or until lightly golden, then trim off the excess pastry (sometimes I don’t bother as people seem to love the crispy bits).
Halve the asparagus spears, saving the tips for the quiche. Chop and place the rest in a large pan over a medium heat with 1 tablespoon of oil. Peel, roughly chop and add the potatoes and onions and strip in half the thyme leaves, and cook for 15 minutes, or until lightly golden, stirring regularly. Pour in the stock, bring to the boil, then simmer for 15 minutes. Whiz with a stick blender until smooth, pass through a sieve, then season to taste with salt and black pepper.
While the soup is on the go, beat the remaining eggs in a bowl with a pinch of salt and pepper and the ricotta, then grate in the Cheddar and pick in the remaining thyme leaves. Chop and add the reserved asparagus tips, then stir into the egg mixture and tip into the tart case. Bake for 40 minutes, or until beautifully golden. I like to serve the quiche and soup together – it’s a wonderful meal.