Line a 20 x 30cm baking tin with baking paper. Find two bowls, and in the first melt the white chocolate and peanut butter together in a microwave stirring every 30 seconds until nice and creamy. Pour the mixture in the baking tin and spread evenly across its base.
In the second bowl, repeat the process with any leftover chocolate, stirring every 30 seconds until smooth. Drizzle this chocolate over the peanut butter mixture.
With a knife, cut through in swirls. Refrigerate until set, then cut into shards to serve.
Always Melt Chocolate Slowly: over a low temperature. The melting point of chocolate is between 30 to 32°C, lower than body temperature.
Melting Chocolate – Microwave: Chop into small pieces. In a clean dry microwaveable dish, melt the chocolate on medium power for 30-second increments, stirring well after each, until melted.
Melting Chocolate – Stovetop: Chop into small pieces and place in the top of a double boiler over hot (but not boiling) water. Stir until melted.
Water & Chocolate: Chocolate is an oil-based product, and oil and water don’t mix. Melted chocolate responds noticeably to small mounts of moisture by transforming it from a shiny, smooth texture to a lumpy, grainy mass (called SEIZING!)
Storing Chocolate: Store chocolate, well wrapped, in a cool dark place (18°C is ideal). If storage conditions are too cold, chocolate will ‘sweat’ when bought to room temperature. If conditions are too warm, the cocoa butter will start to melt out, and a grey ‘bloom’ will form on the surface. This doesn’t affect the flavour of the chocolate, just its look.