Place the heavy cream in a pot and bring it to the boiling pot. Keep aside (hot).

Combine the sugar and glucose in another pot and place on medium heat.

Heat the sugar up until it has a dark golden, amber color. You may need to mix in it with a heatproof spatula to ensure even caramelization. I find medium heat to work best, but it depends on your cooking machine - you may have to juggle between low and medium or high heat.

Once the sugar has the color you want, take is aside and slowly pour in the hot cream, mixing as you pour. Watch out for those hot steams as they can burn as well!

Place the pot back on medium heat and cook the sauce until it reaches 110C.

Take aside and transfer in a jug. Add the butter and fleur de sel and blend 1-2 minutes with a hand blender to ensure proper emulsification.

Transfer in a bowl and cover with plastic wrap.

Refrigerate for 8 hours.