John Whaite's potato, cheese & onion pie

John Whaite's potato, cheese & onion pie

For me the pie is an auspicious symbol (I'm Lancashire-born, and all that). And, of course, the real meaning of pie is hotly debated across the globe; some insist the filling should be entirely enveloped, top and bottom, by golden pastry. Others find contentment with a feeble disc of puff, floating atop a sea of gravy. I'm more evangelical, and believe a pastry base should be present

    • Serves6
    • CourseMain meal
    • Prepare40 mins
    • Cook35 mins
    • Total time1 hr 15 mins
    • Pluschilling

    Ingredients

    For the Pastry

    • 225g plain flour, plus extra for dusting
    • 1 tsp fine sea salt
    • 150g unsalted butter, cubed
    • 75ml whole milk
    • 1 tsp cider vinegar
    • 1 Waitrose British Blacktail Medium Free Range Egg yolk, to glaze

    For the Filling

    • 750g Maris Piper potatoes
    • 1 onion, peeled and quartered
    • 300ml creme fraiche
    • 1 tsp wholegrain mustard
    • 3 salad onions, finely sliced
    • 25g parsley, roughly chopped
    • 3 tbsp finely chopped chives
    • 250g mature Cheddar, grated
    • 200g Gruyère, grated
    • Finely ground white pepper, to season