Sift the seasoned flour into a large bowl. Add the butter and rub into the flour using your fingertips until it resembles fine breadcrumbs.
Sprinkle with 6-7 tbsp chilled water (enough to just bind the dough) and draw the mixture together with a knife. Knead gently on a floured board, then wrap in clingfilm and chill for 30 minutes.
Preheat the oven to 180°C, 350°F, Gas 4.
Divide the pastry in 4. Roll each piece on a lightly floured surface to a thickness of a pound coin, then cut into a circle 18cm/7½in in diameter.
Mix together the vegetables, lamb and mint. Arrange a quarter of the mixture in the centre of each pastry circle and season. Lightly brush the edge of the pastry circles with water then carefully bring up the edges to the centre to cover the filling. Pinch the join to create a sealed edge over the top of each pasty.
Brush the pasties with beaten egg and sprinkle with cracked black pepper. Arrange on a nonstick baking tray and cook in the oven for 1 hour until golden.
Serve hot or cold with chutney or tomato ketchup.
It's a little princess!