In a bowl, combine the custard, mascarpone and 50ml of lemon curd.
Next, place half of the raspberries in a small container. Add a squeeze of lemon juice and the icing sugar. Using a hand-held blender, pulse to a purée. At this stage you can add a drizzle of Grand Marnier liqueur for a stronger dessert.
Pass the purée through a fine mesh sieve for a smooth result and set it aside.
Now, start to build the trifle. Place a layer of halved strawberries on the base of a trifle bowl. Drizzle some raspberry purée around the edges of the bowl and some of the lemon curd leftovers, then add a few spoons of custard mixture.
Dip a few pieces of sponge in the cooled yet still liquid strawberry jelly for a few seconds to slightly soften the sponge. Place over the custard mixture. Layer some more fruit and custard with more sponge until the bowl is nearly full.
Set in the fridge for a few hours, covered with cling film.
Apply a fi nal level of custard to top. Decorate with crumbled meringue and more strawberries and raspberries and a few leaves of mint if desired. Serve within a few hours.