This delicious tart is easy to make, no messing around with tart pans. An elegant first course or lunch.
Preheat oven 375F.
Simmer apple slices in cider until they just start to turn tender, about 2-3 minutes, remove and set them aside. Simmer the remaining cider to reduce to about 2 tablespoons. Toss the apple slices in the reduced cider with the rosemary.
Roll puff pastry out to a 16x10-inch rectangle. Score a line around the puff pastry about ½- inch from edge. Spread mustard over the pastry inside the scored line followed by ¾ of the cheese. Spread the apples over the cheese and mustard and top with remaining cheese. Brush the outer edge of the pastry with olive oil.
Bake until the cheese has melted and the pastry is golden brown, about 15-20 minutes.
Meanwhile toss the arugula in the oil and lemon juice and season with salt and pepper. Serve the tart topped with arugula.