Mix all ingredients together well and season with salt and pepper. I can`t say what the mayonnaise tastes like if you don`t use Dijon mustard. Dijon mustard has a unique taste! If you don`t have brandy rouge, just take normal ones.
You can easily make the red wine vinegar yourself: Simply buy vinegar essence and mix a little with red wine. This vinegar holds up very well. I`ve had mine in the bottle for half a year.
The mayonnaise tastes very good even without the brandy, but the small alcohol note has something special.