Preheat the oven to 350ºF (180ºC).
1. In a medium-sized non-reactive saucepan, heat the lemon juice, zest, sugar, butter, eggs and egg yolks. Have a mesh strainer nearby.
2. Stir until the butter is melted, then whisk the mixture continuously until the mixture thickens and holds its shape when you lift some of it up with the whisk and it visibly mounds up when dropped back down over the rest of the mixture in the saucepan. It should just take a few minute.
3. Pour the warm lemon curd though a strainer into a bowl (or directly into the tart shell), scraping with a rubber spatula to press it through.
4. Smooth the lemon filling in the prebaked tart shell and pop it in the oven until the curd is just set. It’ll take about 5 to 6 minutes.
5. Remove from the oven and let cool before slicing and serving.