Blueberry & ginger: Swap the lemon curd for stem ginger preserve (or a little finely chopped stem ginger and clear honey). Stir it through the mascarpone, then top with blueberries instead of strawberries.
Chocolate, orange & hazelnut: Spread orange curd over the base of the tart case in an even layer (about 0.5cm thick). Omit the lemon curd and zest and add cooled, melted chocolate (or some hazelnut spread) to the mascarpone (at room temperature). Stir thoroughly and spread evenly on top of the curd. Finish with a scattering of orange zest and chopped toasted hazelnuts.
Peanut butter, jam & Banana: Carefully ripple raspberry jam and smooth peanut butter through the mascarpone, instead of lemon curd and lemon zest. Arrange sliced banana on top and finish with roughly chopped roasted salted peanuts.