For the Mediterranean Lamb

• Finely chop the shallot, celery and leek and fry in 2 tablespoon oil until beginning to soften. Mince the garlic, add to the pan and cook for a further 2 minutes. Remove the vegetables from the pan
• Add the lamb to the hot pan and cook, stirring frequently, until browned. 
• Dice the chorizo, add to the lamb and cook for 3 minutes. Drain off any excess fat from the pan
• Return the vegetables to the pan, along with the red pepper (chopped small), the green olives (quartered) and the oregano, cook for 5 minutes
• Pour in the tomatoes and let everything bubble away for 10-15 minutes until most of the liquid has evaporated
• Stir the red pesto through the mixture, season to taste and set aside to cool completely (spoon off any pools of oil as they form (or use a piece of kitchen towel to absorb it)

For the Shortcrust Pastry

• Put the flour and salt into a large mixing bowl and stir briefly
• Cube the butter and add to the bowl. Rub the butter into the flour, using the tips of your fingers, until the mixture looks like fine breadcrumbs and all large chunks of butter have been broken down
• Add half the water and stir with a blunt knife, until the dough just comes together - add more water, little by little, as necessary. Aim for a soft, but not sticky dough
• Tip onto a lightly floured work surface, knead very briefly, form into a ball, wrap in clingfilm and chill for 30 minutes

Assembling the Pastry Pie

• Preheat (fan) oven to 180C/ 350F/ GM4 
• When the meat is completely cool, take the pastry out of the fridge and chop in half (with one 'half' being slightly larger than the other 'half')
• Roll the pastry out on a floured work surface to 2-3mm thick and use to line the pie tin. Brush the edges with a little beaten egg
• Pile the lamb filling into the pastry case
• Roll out the remaining pastry and use to top the pie. Press the edge of the pastry to seal the pie and trim the excess pastry with a blunt knife. Use a sharp knife to make slash lines around the edge of the pie for decoration (see images) or, if you are feeling fancy, re-roll any off-cuts of pastry and use to decorate the pie (e.g. leaves, lettering etc...)
• Brush the top of the pie with beaten egg, make a slit in the centre of the pie to allow steam to escape and bake for around 40 minutes until the pastry is crisp and golden

Assembling the Potato Pie

• Preheat (fan) oven to 180C/ 350F/ GM4 
• Peel and boil the potatoes in salted water, then mash until smooth, adding the butter and sufficient milk to create a soft & creamy consistency. Season to taste
• Divide the lamb between 4 individual pie dishes and top with the potato (pipe it on for a neat finish). Alternatively, use a 20 cm circular pie dish.
• Scatter a few breadcrumbs over the potato and bake for 30-40 minutes until golden

Serve either pie with fresh salad or buttered green vegetables