Preheat the oven to 200°C and line a baking sheet with baking paper.
Place the dough on the baking sheet and stretch it out as thinly as possible.
Mix the crème fraîche, mascarpone, nutmeg, salt and pepper.
Spread this evenly over the dough.
Top with the onions, lardons and thyme.
Pop in the oven for 20-25 minutes and serve with an aromatic Riesling.