This recipe has been designed to be made ahead and frozen – a family-friendly batch pie, with cheesy mashed potato atop hidden broccoli, leeks and celery
Prep:20 mins
Makes 8 individual pies
500g slim young leek, thickly sliced300g broccoli, cut into small florets3 celery sticks, de-stringed and sliced1 ½kg floury potato, such as King Edward, cut into even-sized chunks85g butter170g pot 0% fat Greek yogurt850ml semi-skimmed milk75g plain flour2 tsp English mustard1 tsp wholegrain mustard300g pack mature cheddar, finely gratedhandful frozen peas
STEP 1Bring a large pan of salted water to the boil. Put the leeks, broccoli and celery in a large steamer. Add the potatoes to the water and cook for 20 mins, with the vegetables steaming on top, until all are tender. Drain the potatoes, then mash with plenty of seasoning, 25g of the butter and all the yogurt.STEP 2While the veg cooks, pour the milk into a pan, add the flour, both mustards and remaining butter, and cook over a medium heat, whisking all the time, until smooth and thickened. Stir in half the cheese and season. Remove from heat.STEP 3Divide the steamed veg and peas between 8 individual pie dishes. Pour over the sauce and top with the mash, then sprinkle over the remaining cheese.STEP 4Pack into freezer bags and use within 3 months. To serve, unwrap and put the dishes on a baking tray in the cold oven, then set to 200C/180C fan/ gas 6. Bake for 50-55 mins until bubbling and hot all the way through.
