Line a 9x9" square tin with parchment paper and leave to the side for now.
Blitz the biscuits in a food processor until they are a fine crumb – mix in the melted butter and condensed milk blitz again until combined!
Press into the bottom of the tin and chill whilst you make the icing!
Mix the icing sugar, peppermint essence, and food colouring and enough water till it forms a relatively thick paste – spread across the biscuit base.
Start with less water and gradually add in a tiny amount more – you don’t want it runny, you have to be able to spread it but still be thick. Leave to set for an hour.
Melt the chocolate in a heatproof bowl and pour on top of the icing (trying not to disturb the icing too much) and leave to set in the fridge till solid, so probably an hour or two!
Cut the mint slice into 16-25 pieces and enjoy!
Notes
Keep in an airtight container in the fridge so that it doesn’t melt everywhere!
This will last in an airtight container in the fridge for one week!
You don’t have to include the condensed milk in the base but I prefer it to be slightly softer! If you don’t want to use it, bump the butter up to 200g.
You can use 1-2tbsp of oil in the chocolate to make it easier to cut after it has set if you prefer!