Apple, cheese & potato pie
SERVES 4-6 PREP 25 mins plus 30 mins chilling COOK 1 hr 15 mins MORE EFFORT V
30g salted butter1 tbsp vegetable oil2 large onions, halved and finely sliced½ bunch of thyme, leaves picked30g plain flour500ml vegetable stock1 tbsp wholegrain mustard1 tbsp white wine vinegar450g potatoes (we used3 apples, peeled, cored and chopped into 1-2cm chunks150g mature cheddar, grated
