Butter the sides and bottom of an oven-proof dish (or your fave vintage cast iron skillet, it's up to you)
Cut the slices of St Pierre Chocolate Chip Brioche Loaf into small triangular pieces, and place in the dish (or use another loaf of rich, cakey bread from your leftovers like—challah works nicely as well).
Place a large mixing bowl on top of a pan of simmering water
Melt the chocolate, butter, sugar and cream in the bowl and stir gently
Beat the 3 large eggs together in a separate bowl
Mix the beaten eggs with the chocolate mixture, and pour over the brioche
Place the ovenproof dish into the fridge to chill—leave it overnight if possible, or just watch a movie and come back to it in a couple of hours
Preheat the oven to 350°F and bake for 25-30 minutes