Preheat your oven to 200℃/395℉ (fan-forced).
Line a 24 x 33cm slice tin with non-stick baking paper. It's important the tin is this size otherwise the roulade will be too thick and won't roll without splitting.
Grate the zucchini. Toss with the sea salt in a colander and leave 30 minutes. Rinse and squeeze dry in the sieve and then in a clean cloth or tea-towel.
In a mixing bowl, beat in the egg yolks, herbs and Parmesan and season with sea salt and pepper. Once the zucchini is ready, add this and mix well.
In a separate clean bowl, whisk the egg whites with the cream of tartare until peaks just form. Thermomix, butterfly inserted, 1 min 30 sec, speed 4.
Gently fold the egg white into the courgette/ egg yolk mixture using a large spoon. You are aiming to just combine the ingredients without over working the mixture.
Pour into prepared tin and quickly level the mixture, spreading it out into the corners. Bake for 13-15 minutes until set and light golden brown.
Whilst that's baking, crumble the salmon into a bowl with the finely grated lemon zest, capers, spring onion and crème fraîche, quark and lemon juice. Season with sea salt and pepper. Mix until almost smooth. Thermomix 20 seconds, speed 3.
Taste the mixture and season with salt, pepper and more lemon juice if you feel it's needed.
Store the salmon mixture in the fridge until required.
When the roulade is cooked, invert it onto a clean tea towel. To do this easily, I wrap the tea-towel around the baking tin then tip it over.
Peel away the baking paper carefully and loosely roll it up from the short side (so it's like a Swiss roll). Allow it to cool fully.
When its cooled completely, carefully un-roll the roulade and spread it with the salmon cream filling. Roll-up again from the short side, then carefully transfer to a serving plate with the seam-side down.
Chill and store in an air-tight container until ready to serve.