First make the pastry. Rub the fats into the flour until it's all crumbly, then add a little water until it comes together into a smooth dough. Leave to rest in the fridge until needed.

Preheat the oven to 180C. Pop the lamb, veg, mustard, herbs and stock into a baking dish. Roll the pastry to the thickness of a pound coin and cover the pie. Slash the lid to allow the steam to escape, and brush with an egg or milk wash if you have some spare. If you've got some, a little sprinkle of coarse sea salt on top will be a great flavour punch. Pop in the oven and bake for 30 mins until golden and risen. Serve with greens and gravy.