Yes, you can make these stilton and walnut tarts into a large flan. Line a suitably sized flan dish with the pastry and follow the steps given above to blind-bake the pastry shell. Fill the pastry with the filling and bake in the oven for the temperature given in the recipe. You may find that you need to bake the pie for a few minutes longer. When I made this recipe I only had 8 flan cases so I used the remaining pastry and filling to make a larger tart. (I think I should have taken a bit more trouble and crimped the edges of the pastry, but I'm sure you'll get the idea :) ).