1 Preheat oven to 200-220°C. Place the crust in the baking dish. Spread the mustard evenly on the bottom.
2 Layer the ham (cut into strips) and the tomatoes (sliced, avoiding adding too much juice to avoid making the crust soggy) on top evenly.
3 Pour the crème fraîche mixed with salt and pepper on top, then sprinkle grated gruyère cheese all over.
Finally, bake for about half an hour.