Montezuma's Dark Chocolate Fudge

Ingredients:

• 397g tin condensed milk
• 450g light brown soft sugar
• 120g  butter, cubed
• 125ml milk
• 5g salt
• 300g Montezuma’s dark chocolate buttons

Method:

1. Line a 20cm/8inch square tin with baking paper. 
2. Place all of the ingredients, apart from the salt and chocolate, into a large, dry saucepan over a low heat. Continuously stir until the butter has melted and the sugar has completely dissolved. 
3. Slowly bring the mixture to a rolling boil over a medium-high heat. Stir continuously, especially around the edges, to stop the mixture catching on the bottom of the pan and burning. Be very careful as the mixture is very hot.
4. Once the mixture has started to boil vigorously use a sugar thermometer to bring the mixture to 115C, stirring constantly.
5. Add the salt then beat the mixture well. 
6. Leave to cool in the saucepan for 10 minutes stirring occasionally.
7. Stir in half the dark chocolate beat again. 
8. Pour into the lined tin and level with the back of a spoon. 
9. Stud the mixture with the remaining chocolate couverture
10. Refrigerate for at least 2 hours, or until completely firm and you can cut through it easily with a knife without it getting stuck. 
11. Remove the fudge from the tin, transfer to a chopping board and cut into squares with a sharp knife.