Preheat oven to 350°.
Slice the spinach and leek, in a frying pan, heat 2 tablespoons of olive oil over medium heat, add the garlic cloves, spinach and leeks, let them cook until tender, about 10 minutes. Set aside.
Combine the eggs, cream, salt and pepper in a bowl. Set aside.
With a mandolin or a food processor, cut your potatoes really thin, season well and cover an oiled baking dish, distribute the potatoes evenly into bottom and sides to form crust. Drizzle remaining 2 teaspoons oil over crust.
In a large bowl, mix together spinach mixture and the bacon, combine well and place over the potatoes, distribute evenly on the baking dish. Pour egg mixture over , spreading with the back of a spoon to distribute evenly.
Bake for 40 to 50, until puffed and golden. Let cool on a wire rack 10 to 15 minutes before serving.