Make a classic béchamel. In a saucepan, melt 30g (1oz) of butter and add 30g (1oz) of flour, stirring until a paste forms.
Lightly cook this for one minute on low heat, being careful not to burn the paste, then add 100ml (3 1⁄3 fl oz) of milk, and continue to stir over a medium heat until the béchamel sauce has thickened considerably.
Cut the cauliflower into very small pieces, as the condiment will be coarse in texture.
Warm the olive oil in a pan and add the cauliflower, lightly roasting it until it starts to turn light golden in colour.
Add the butter to the pan and continue to colour the cauliflower. Once nicely golden, remove the excess fat from the pan with some paper.
Add the grated Comté to the pan with the cauliflower, and continue cooking until the cheese has turned golden in colour, mixing the ingredients continuously.
Remove the pan from the stove, and add the béchamel, salt, lemon zest, and the diced hard-boiled egg.
Spoon the warm condiment into a piping bag.