75 g (3 oz) Swiss cheese, such as Emmental, grated
½ teaspoon dried thyme
green salad, to serve (optional)
Place the oil in a large frying pan over a medium heat and fry the lardons for 3–4 minutes, until cooked but not browned. Remove with a slotted spoon and drain on kitchen paper.
Place the pastry on a baking sheet lightly dusted with the cornmeal. Spread the crème fraîche over it, leaving a 1 cm (½ inch) border all around the edge.
Scatter the onion and cheese over the crème fraîche, followed by the lardons and finally the thyme. Bake in a preheated oven, 220˚C (425˚F), Gas Mark 7, for 12–15 minutes, until crisp and golden, then serve with a green salad, if desired.