Never heard of grape must mustard? Think of it as a milder, sweeter version of wholegrain mustard and you are getting close. Here its used in a dish that sits somewhere on the spectrum between bread sauce and bread stuffing, so you could see it as an alternative to either or as the missing part of a holy trinity of bread greatness. The dried porcini mushrooms add some serious depth of flavour and help make this a dish that would be excellent as part of a Sunday roast, any time of year
Place the milk in a large saucepan and add the porcini mushrooms. Bring to the boil, stirring frequently, then turn off and allow to infuse for at least 30 minutes.
Butter all the bread on one side then spread with the mustard.
Beat the eggs in a bowl and add the cream. Pour over the infused milk and season with salt and plenty of black pepper.
Arrange the bread in a deep dish or roasting tray in rough layers so that some will be submerged, and some will crisp up on top. Pour over the milk mixture and squeeze the bread down. Allow to absorb for 30 minutes.
When ready to cook, heat an oven to 180C fan / 195 non-fan. Place the dish in the oven and cook for 30- 40 minutes, or until nicely browned on top and hot in the centre.