In the cup of a high speed blender combine all the ingredients and blitz until very smooth. You may have to stop blending, remove the cup, tap it on the counter and then continue to blend in order to get all the bits of hazelnuts nice and smooth. Set aside.

Throw the blackcurrants in a small high-sided saucepan with around 3 tablespoon water. Bring to a simmer, stirring constantly. Simmer until all the currants are burst and you have a nice thick fruit pulp (about 3-4 minutes).

Reduce the heat to low, add the sugar and lemon juice. Stir until the sugar is completely dissolved. Turn the heat up to medium and boil the mix for another 3 minutes. Turn off the heat and set aside to cool completely.

In a dry frying pan over medium heat, place the brioche slices and toast lightly. Flip and repeat on the other side. Allow the brioche to cool slightly before topping with two good tablespoons of the tahini. Push the tahini to the edges of the brioche, leaving a well in the middle of the slice. Add a good tablespoon of the cooled jam. Top with the toasted chopped hazelnuts and serve.