This is an excellent recipe that I made the other day. I don't usually have luck with meringue pies - mine usually 'weep' meaning that moisture comes out of the meringue, but this one is made of cast iron.

I didn't have the lemon extract, but it was fine without it.

Lemon Pie:
1 baked 9 inch pie shell
1 1/4 cups sugar
6 tablespoons cornstarch
2 cups water
1/2 cup lemon juice
3 egg yolks
1 1/2 teaspoons lemon extract
2 teaspoons vinegar
3 tablespoons butter

Mix sugar and cornstarch together in the top of a double boiler. Add the two cups water. Combine egg yolks with lemon juice and beat until well mixed. Add to the rest of the sugar mixture. Cook over boiling water until thick, about 25 minutes. This does away with the starchy taste. Now add the lemon extract, butter and vinegar, and stir thoroughly. Pour mixture into deep 9 inch pie shell, and let cool. Cover with meringue and brown in the oven.

Meringue:
1 tablespoon cornstarch
2 tablespoons cold water
1/2 cup boiling water
1 teaspoon vanilla extract
3 egg whites
6 tablespoons white sugar
1 pinch salt

Blend cornstarch and cold water in a saucepan. Add boiling water, and cook until thick and clear. Cool completely.
Beat egg whites till foamy. Gradually beat in sugar, beating until stiff and glossy. Add salt and vanilla, and slowly beat in cold cornstarch mixture. Beat quickly for several minutes. Spread meringue on filled, cooled 9 inch pie.
Bake at 350 degrees F (175 degrees C) for 10 minutes.