Pre-heat the oven to 190 C and generously grease a deep spring-formed cake tin with butter.
Pastry - add the plain flour and butter to a food processor and pulse until it forms breadcrumbs (or rub in by hand if you don't have a food processor). Then add the water and the egg, and pulse to bring it together into a ball. Rest in the fridge, covered in clingfilm for ten minutes.
In a frying pan, dry fry the spinach until wilted. Allow it to cool on a plate then use your hands to squeeze out the extra liquid.
Roll the pastry out reasonably thinly and use it to line your tin. I pressed the pastry up the sides a bit, and I leave it fairly uneven because I like it to look a bit rustic.
Prick the base of the pastry with a fork and blind bake it for ten minutes in the oven. Use baking beans to weigh the pastry base down if you have some. I didn't and I chanced it, I was lucky that the base didn't bubble up!
Spread the cooled spinach over the base of the part baked casing. then add a layer of half of the cheese over the spinach.
In a separate bowl, whisk together the eggs, cream, most of the remaining cheese (apart from a small handful of the grated cheeses) and a good twist of salt and pepper. Pour this mixture into the pastry case. Top with the remaining cheese and more salt and pepper.
Bake for 45-50 minutes, until the top is set and golden. Allow the quiche to cool completely in the tin, sitting on a wire rack. Then when cool, carefully push it up from the base to remove. Use a pallet knife to remove it from the base.
