Heat the oil in a large frying pan, add the vegetables and cook for 4-5 minutes, stirring regularly. Add the herbs and 125ml water, cover and cook for 6-8 minutes until the vegetables are tender. Add the gravy granules and mix well. Transfer to a bowl and allow to cool, then mix in the beef.
Meanwhile, preheat the oven to 190°C, fan 170°C, gas 5. Cover a large baking sheet with baking paper. Divide the pastry into 6 equal pieces and roll each into a ball. On a lightly floured surface, roll each ball out into a circle about 18cm across.
Brush the edge of each pastry circle with beaten egg. Divide the filling evenly and spoon into the centre of each circle. Fold the sides of the pastry up, so that they meet in the middle, and crimp the edges. Transfer to the baking sheet and brush all over with egg. Make a couple of air holes in each pasty then bake for 30-40 minutes until golden and crisp. Serve with the salad.