Make sure all your ingredients are made well in advance and completely cold. You could add some roasted macadamias to this shortbread crumble.
Place the cooked shortbread base into the Thermomix bowl in pieces (maybe not all of it, use your judgement) with the nuts if using. Crush 2 sec/speed 5.
Add the lemon butter and mascarpone and insert Butterfly. Whip until soft peaks form 10-20 sec/Butterfly/speed 4. DO NOT OVER WHIP.
Assemble by placing plenty of berries into the bottom of each serving glass or bowl, top with the whipped mixture and serve. There is a nutty crunchy element to the dessert, it has the sour/sweetness of the berries and is kind of like an Eton mess without the meringue!