This French classic is traditionally made with béchamel sauce;
our method is simpler and uses crème fraîche. Top it with a fried
egg and you have a croque-madame.
200 gmcoarsely grated Gruyère200 gmcrème fraîche3 tspDijon mustard8thick sourdough bread slices8thick slices of leg ham, off the bone40 gmbutter, coarsely chopped
Preheat oven to 180C. Combine Gruyère, crème fraîche and mustard in a bowl, season to taste, mix well. Spread thickly over bread slices, then top half the bread slices with ham. Top with remaining bread slices, cheese-side up, and set aside.
Melt half the butter in a frying pan over medium heat until foaming, add half the sandwiches, cheese-side up, cook until base is golden (1-2 minutes), transfer to a baking-paper-lined oven tray. Wipe out pan with absorbent paper, repeat with remaining butter and sandwiches. Bake until bubbling and golden (5-10 minutes), serve immediately.