Pre-heat the oven to 200 degrees Celsius.
Line individual tart moulds with the puff pastry rounds, ensuring that the pastry is gently pushed into the edges of the moulds.
Line the pastry with grease proof paper or a double layer of cling film. Fill with baking beans or raw rice. Place the moulds in the oven and bake for about 15 minutes or until the pastry edges are golden brown.
Remove from the oven and take away the baking beans/rice.
Return to the oven for 3-5 minutes then remove and allow to cool.
Zest and juice the lime and lemons. Place the zest and juice in a sauce pan with the sugar and butter.
Bring to the boil and simmer until the mixture becomes bubbly and sticky.
Remove from the heat and set aside.
Place the 7 whole eggs into a heatproof bowl and whisk together over a pan of simmering water.
Keep whisking until the eggs start to thicken.
Now mix this egg mixture with the lemon mixture and pour into the cooked pastry cases.
Place in the fridge to set.
Whisk the egg whites with the 175g sugar until you achieve stiff, glossy peaks.
Spread or pipe this mixture on top of the set lemon tarts and use a chef's blow torch to gently colour the meringue - you are aiming for a light golden brown colour.
«Replace the lemons and limes with oranges to make a rich orange tart.»