Begin by making the strawberry conserve, place the strawberry puree, strawberries and 35g of the sugar in a small saucepan and bring to a boil.
Place the remaining sugar and pectin in a bowl and stir together, add to the boiling conserve and stir to combine. Boil the conserve until it reaches 104C and then pour the conserve into a sterilized jar, cover the surface of the conserve with clingfilm, make sure it touches and leave to cool.
Next make the creme patissiere for the creme diplomat, soak the gelatine in the bowl of cold water.
Place the egg yolks and sugar in a bowl together and whisk until pale in colour. Add the flour and whisk again until fully combined.
Place the milk and vanilla bean paste in a saucepan and bring to the boil, slowly add the hot milk to the egg mixture and stir to combine. Add the hot milk a little at a time so you don't risk cooking the eggs.
Return the mixture to the saucepan and stir until thickened, take the gelatine and squeeze out the excess water. Take the creme patissiere off the heat and stir in the gelatine until it has dissolved.
Place the creme patissiere in a bowl and cover with a layer of clingfilm - make sure it touches the surface and place somewhere to cool. Then put in the fridge.
Next make the sable breton pastry, whisk the sugar and eggs together in a medium sized bowl until light and fluffy.
Add the softened butter to the sugar and egg mix and stir until combined. Add the flour, baking powder and salt and stir until the pastry begins to come together. Keep mixing until it forms a dough.
Turn the dough out onto a piece of greaseproof paper and pat it out to flatten it. Take another sheet of greaseproof paper and place it on top. Roll the pastry out to a thickness of 8mm. It will be very soft, place it in the fridge to firm up for at least an hour.
Preheat the oven to 180C and take the pastry from the fridge, cut out a circle that is 16cm in diameter. You can either use a cake ring to cut out the circle of pastry, or using the ring from a loose-bottomed cake tin, place it on the pastry and use it as a guide to cut the pastry out with a knife.
Place the pastry on a prepared baking tray - lined with a silicone baking sheet or baking paper and place the cake ring or cake tin (without the base) over the pastry, so that it is inside the tin. This will stop it spreading and encourage it to rise, rather than bake outwards.
Bake for 20-25mins until golden brown, remove from the oven and leave to cool in the ring. Remove it from the ring once cool and trim the edges if need be.
Next make the creme diplomat, take the whipping cream and place it in a bowl and whip it until it forms soft peaks. Take the creme patissiere and stir it to loosen it a little. Slowly fold the whipped cream into the creme patissiere to lighten it. When fully mixed place the creme diplomat in a disposable piping bag and place in the fridge for 30 mins to firm up.
To assemble the strawberry sable breton take the sable breton base and place it on a plate or cake board. Take the strawberry conserve and stir it to loosen it, place it in a piping bag and cut the end. Pipe a neat spiral from the centre of the tart to about 2cm from the edge of the tart. You may not use all of the jam, this is fine.
Take the creme diplomat from the fridge, cut a 1cm size tip from the piping bag and pipe a spiral starting from the outside, working towards the centre. Leave a 1cm gap from the edge of the pastry base and just use enough creme to cover the jam, you won't use all of the creme diplomat.
Take the strawberries and cut the top of the strawberries and slice/half/quarter them however you feel based on your size of fruit. Arrange the fruit in a ring around the outer edge of the creme diplomat and then fill in the centre with more fruit. When you've finished with the strawberries, decorate with some of the raspberries / redcurrants, or just leave it as all strawbwerries.Using a sharp knife take small pieces of the gold leaf and decorate the strawberries with it. This is best eaten on the day you make it as the sable breton base begins to soften and the strawberries will start to weep. If you don't mind this, it will keep comfortably in the fridge for at least 2-3 days.