Line a 7 inch round baking dish with parchment paper - see above if you need help on how to do this!
Place the yogurt into a medium sized bowl.
Add the eggs two at a time and whisk in to the yogurt mixture.
Add the vanilla and whisk.
Add the cornstarch and whisk until you have a smooth, lump free batter.
Carefully pour the batter in to your prepared dish.
Place in the centre of the oven for about 45 minutes to 1 hour or until the tart has puffed up and turned a lovely golden brown colour. It should still have a slight 'wobble' in the centre!
Remove from the oven and set aside to cool at room temperature for 30 minutes.
Remove from the dish and place the tart on a plate and chill in the fridge for a further 60 - 90 minutes.
Slice into 6 equal portions and serve cold with berries or a spoonful (or two!) of sugar free jelly (jam!).
Notes
The tart will puff up a lot when baking. When removed from the oven the tart will 'deflate' but this is normal!