First melt the butter on a medium heat. Now add the flour and toast the flour for 2 to 3 minutes.
When it has a nutty smell while stirring add the cream and the milk. Do this in 3 parts to prevent lumps from forming.
Once it has boiled turn off the heat and season it with the chili flakes and the grated old cheese. Mix it well and if needed season it with black pepper and salt. Then cover it with wrap and let it cool down in your fridge. After that fill a piping bag and keep it covered in your fridge for later.Â
