Preheat oven to 400 degrees.

On a flat, floured work surface, roll out puff pastry to an 18-inch square. Trim the puff pastry to a XX-inch circle and cut a small X in the center. Add the puff pastry to a flat baking sheet or large enough plate to freeze for 20 minutes.

In the Le Creuset Tart Tatin dish, melt butter over medium-high heat with ginger, vanilla bean, and lemon juice. Once melted, remove the pan from heat and remove the vanilla bean. Sprinkle with sugar and salt. Add plums, cut side down, forming concentric circles (as best you can) in a single layer.

Return dish to heat and bring to a simmer. Cook for 7 minutes without stirring or moving any of the plums. Remove from heat and top with the puff pastry circle.

Bake for 30 to 35 minutes, until the crust is deep golden brown and the juices have thickened. Let cool on wire rack for 10 minutes.

Invest onto a platter. Serve warm.