Zest and juice the lemons.
Place the zest and juice in a saucepan with 1/3 cup (60 grams) of fructose, 3 whole eggs, and 3 egg yolks.
Bring to a boil while stirring, then add the cream.
Cook over very low heat, stirring constantly with a spatula or whisk, until it comes to a boil and thickens. Be careful to cook gently to avoid scrambling the eggs. It may take a while for the mixture to thicken, but keep the heat low.

Beat the remaining 3 egg whites until stiff peaks form, then add 1/4 cup (50 grams) of fructose.
Continue beating until glossy peaks form.
Pipe or spread the meringue over the cooled lemon tart using a piping bag with a large star tip, or simply spread it as evenly as possible.

Chill until ready to serve.
Loosen the edges of the tart with a knife.
Brown the meringue with a kitchen torch.
OR
Brown the meringue in a hot oven under the broiler.
Place the tart in the middle of the oven under the broiler on high.
It takes about 15 minutes for the top to become golden brown.

You can also make an Italian meringue for a firmer topping (see photo).