Meanwhile, place the heavy cream, salt and 1 teaspoon of the orange zest into saucepan on medium heat and simmer for 3 minutes.
Remove from the heat and allow to cool for 5 minutes.
Meanwhile, place the egg yolks, sugar and remaining orange zest in a separate bowl and whisk until the eggs are pale, thick and fluffy, approximately 1 minute.
Slowly pour ¼ of the warm cream into the eggs, whisking to incorporate and heat the eggs slowly, continue with the remaining cream in stages until completely combined.
Add the orange juice to the custard mixture and whisk to combine.
Pour the orange custard into your tart shell, straining, if you prefer. Place the dish into a large baking tray.
Boil water and pour the water ⅓ up the sides of the tart dish into the large baking tray.
Slide carefully into the oven and bake for 50 minutes or until it is lightly golden on top and only slightly jiggly in the center.
Remove and allow to cool to room temperature.
Place in the fridge for minimum 1 hour to chill.
Remove when ready to serve and sprinkle a further 30 grams / 2 tablespoons sugar evenly over the top.
Carefully caramelize the top either with a blowtorch or under the grill or broiler until bubbling and charred.
Tap, slice and serve.
Enjoy