1. Line a baking sheet with parchment paper.
2. Coarsely chop the dark chocolate and white chocolate into pieces, keeping them in separate piles.
3. Use a double boiler to melt the dark chocolate. If you don't have a double boiler, you can set a heatproof bowl over a saucepan of gently simmering water. Be careful the bowl doesn't touch the water.
4. Once two-thirds of the dark chocolate has melted, remove the saucepan or bowl from heat. Stir the chocolate mixture until completely melted.
5. Repeat the melting process for the white chocolate, using a clean inner saucepan or bowl.
6. Use a spatula to spread the dark chocolate onto the parchment paper.
7. Drop spoonfuls of white chocolate randomly over the dark chocolate, and use the tip of a knife to swirl them together.
8. Scatter almonds across the chocolate mixture.
9. Place the baking tray in the fridge. Wait for the chocolate to harden, about an hour. When ready, break the chocolate into pieces, and enjoy!