Meringue: Begin beating the egg whites with a mixer or stand mixer. When the whites start to foam, add a spoonful of sugar and the lemon juice. Wait a bit, then gradually add the rest of the sugar, waiting a little between each addition so the sugar dissolves. The meringue is ready when it forms stiff peaks that hold their shape when you lift the whisk.

Transfer the meringue to a piping bag and pipe 4 discs onto a baking sheet lined with parchment paper to make bases for 4 individual Mont Blancs. Pipe the remaining meringue into small mounds for decoration.

Bake at 210°F (100°C) for about 1 1/2 to 2 hours, opening the oven door every 30 minutes to let out moisture. The meringues are done when they lift off the paper easily.

Whip the cream until stiff peaks form, then gradually add the sugars to stabilize it. Place the whipped cream in a piping bag fitted with a star tip and refrigerate.

Blend the chestnuts with the sugar and a little water. Add more water if the mixture is too thick, and more sugar to taste. The texture should be smooth and slightly soft. Place in a piping bag with a fine tip and refrigerate.

To assemble, place a meringue disc on a plate. Pipe a mound of chestnut cream in the center, making spaghetti-like swirls. Top with small dollops of whipped cream and decorate with the small meringues and pieces of candied chestnuts.