Tart base

• Put your biscuits in a bag, seal it tightly. Slam the bag on a countertop a few times and possibly crush the remaining biscuits with your fingers. Alternatively, put them in a food processor and chop them finely.
• Melt the butter and mix it with the biscuits. This makes a fine biscuit base that needs to be pressed into 4 small tart forms.
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• Crack the eggs and separate them into yolks and whites in two different bowls. The whites are for the meringue, while the two yolks go into the filling. The remaining two yolks should "just" be put back in the fridge and used for something else. This could be, for example, salt-cured egg yolks or a homemade Béarnaise sauce.
• Grate the zest of one lemon with a grater. Be careful not to include the white part, as it tastes bitter.
• Squeeze the juice from 2 lemons.
• Put the egg yolks, lemon juice, lemon zest, and 1 can of condensed milk in a large bowl and whisk it all together - preferably with a whisk.
• Pour the mixture into the biscuit bases and bake in the oven for 15-20 minutes at 180 degrees Celsius (356 degrees Fahrenheit) conventional oven.
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• Whisk the egg whites and sugar together in a mixing bowl. This can easily take 5-10 minutes, making it appropriate to do while the tarts are in the oven.
• When it becomes stiff and shiny, it is ready.
• Pour the mixture into a piping bag with a nozzle of your choice.
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• Take the tarts out of the oven and turn it down to 150 degrees Celsius (302 degrees Fahrenheit) (perhaps with the door open for a few minutes to speed up the process).
• Pipe your meringue in any pattern on top.
• Put them back in the oven at 150 degrees Celsius (302 degrees Fahrenheit) for about 10 minutes - the meringue should become slightly golden.
• Let them cool down a bit before serving and, if you like, lightly torch the meringue with a blowtorch for extra color.
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