White chocolate and rhubarb trifles

1. Preheat the oven to 200˚C, gas mark 6. Toss the rhubarb, sugar, 50ml rum (or orange juice) and ginger together in a baking dish and spread out in a single layer. Cover with foil and roast for 15 minutes. Uncover and baste with the juices. Roast for another 5-10 minutes, until the rhubarb is tender, but not collapsed. Set aside to cool then remove the ginger.

2. Divide the biscuits between 4 glasses or glass serving bowls, breaking them into pieces to make them fit. (Alternatively, use one medium-sized trifle bowl.) Sprinkle evenly with the remaining 50ml rum (or orange juice). Spoon the rhubarb and cooking juices over the biscuits.

3. For the ganache, chop the white chocolate and put in a heatproof bowl. Heat 150ml cream in a saucepan until just boiling then pour over the chopped chocolate and stir until the chocolate has melted and the mixture is smooth. Set aside to cool completely. Add the remaining 150ml cream then whip with electric beaters until soft peaks form. Pipe in swirls or spoon over the rhubarb layer. Chill for 2 hours or up to 24 hours. If liked, grate a little extra white chocolate directly over the trifles to serve.