Method

1. Pre-heat oven to 180°C. Lightly grease a 30-33cm diameter pizza pan.
2. In a food processor with the mixing blade in position, mix the flour, margarine and icing sugar together thoroughly.  Add the egg yolks, essence, lemon zest  and water through the chute while mixing, to achieve a firm ball of dough that forms away from the bowl sides.
3. Press the dough evenly into the prepared pizza pan.
4. Spread the lemon curd across the entire base.
5. Rinse and dry out the processor bowl, and insert the whisking attachment into the processor.
6. Whisk the egg whites until just beginning to form stiff peaks. Gradually add the sugar, beating well between each addition.  When glossy firm white peaks are achieved, beat in the corn flour and vinegar.
7. Drop amounts of this meringue across the lemon curd layer, and using small dragging-strokes with a fork, spread the meringue to cover the entire surface, but being careful not to lift the curd and spoil the appearance.
8. Bake for 25 minutes. Set aside. Serve at room temperature.
9. Slice into pizza-like wedges for serving, and lift them out gently using a broad egg-lifter.