Preheat the oven to 350 degrees F.
In a skillet over medium-high heat, render
the bacon until crisp
and golden brown. Add the leeks
and cook until soft. Add the spinach and cream and cook until the cream thickens. Season with salt and pepper.
Place 1 oyster on each shell. Top with a spoonful of the creamed spinach
. Place the oysters onto a baking sheet and top each oyster with Parmesan
. Bake for 5 minutes.