Use this (or your favourite) recipe. Instead of the tart rings, use a scalloped cookie cutter to shape the pastry and fit into the wells of the lightly greased tart pan using a pastry tamper, or your fingers.
Candy the oranges:
Line a baking sheet with parchment paper and place a wire rack on top. Set aside.
Give the orange a good wash and remove the ends. Use a sharp knife to slice the orange into ¼-inch slices.
In a large, shallow saucepan, heat the water and sugar on medium-high to dissolve the sugar.
Bring to a gentle boil without stirring, add the orange slices and cook for 20 minutes.
Lower the heat, add the liqueur, flip the slices and continue cooking on medium-low heat for an additional 20-30 minutes.
The orange slices are ready when the syrup thickens and the peels appear translucent/glassy.
Transfer the slices to the wire rack to cool.
Make the curd:
Add the orange juice to a small saucepan and bring to a rapid simmer over medium-high heat, until reduced to ¼ cup. Pour into a measuring cup to check that it has been reduced enough, if not return to pot and heat some more. This took me just over 5 minutes (original recipe indicated 2-4 minutes).
Pour the juice in a measuring cup and combine with the zest and lemon juice. Set aside to cool to room temperature.
In a separate bowl, whisk together the egg, yolks and sugar. Pour the juice mixture into the egg mixture in a steady stream, while whisking. By adding the warm liquid slowly to the eggs, you are tempering the eggs to avoid ending up with scrambled eggs.
Place a sieve over a clean bowl and set on the counter close to the stove. You will need this for the curd as soon as it reaches the desired temperature.
Pour the juice and egg mixture back into the saucepan and set it over medium heat. Gently stir the mixture constantly until it thickens enough to coat the back of a spoon, or reaches 180ºF.
Remove from heat and pour through the sieve into the prepared bowl. This removes any chunky bits of eggs and zest. If you want the finished curd to have the zest, add fresh zest to the strained curd.
While still warm, stir in the butter, salt, vanilla beans and candied orange (optional)
Allow to cool, then transfer to an airtight jar. The curd will keep in the refrigerator for about a week (but I guarantee you it will not stick around for that long)
Make the meringue:
Fill a heavy duty pot about a quarter of the way with water and place on the stove over medium heat to simmer.
Add egg whites and sugar to your stand mixer's bowl and place on top of the pot, ensuring the bottom of the bowl is not in contact with the water in the pot.
Whisk the sugar and egg white mixture constantly, but gently, until temperature reaches 160°F.
Once at the correct temperature, remove from heat, wipe away the water from the underside of the bowl and transfer to your stand mixer.
With the whisk attachment, begin to whip the meringue until it is thick, glossy, and the bottom of the bowl is no longer warm to the touch.
Notes
Sweet Tip: Don't discard the remaining syrup. You can refrigerate for a few days and use it to soak cake, add to a cocktail, or vinaigrette. When making meringue, always use grease-free utensils and bowls to achieve a fluffy, stable meringue.