Very lightly grease a skillet with olive oil, put in the bacon & sauté until browned. Add the chopped shallot; sauté until softened, then add the leek. Stir together & remove from heat – you want the leeks to keep their color so don’t overcook.
In a bowl, whisk sour cream, eggs, mustard & spices together. Don’t overmix, keep the mixture a little ‘lumpy’.
Preheat oven to 375 F.
Slice the bread, but not all the way through. You need to cut deep enough into the bread to open out the loaf & fill between the slices, while leaving the loaf connected at the base. Place the bread on a sheet of parchment paper.
Into each slot in the bread, place a slice of turkey followed by some of the bacon, shallot & leeks.
Place a large sheet of foil paper on a baking tray. Use the parchment paper to lift the bread & lay on top of the foil. Spoon some of the sour cream/egg mixture into each slot, so that the bread absorbs as much as possible.
Finally, insert the slices of cheese. Enclose the loaf fully in the baking paper & then wrap it in the foil to make a tight parcel.
Place the wrapped bread into preheated oven for about 55 minutes, then OPEN out the foil & parchment paper. Place bread back in the oven until the top of the bread & its filling is golden brown. Remove from oven & serve hot.