With the rack in the middle position, preheat the oven to 200 °C (400 °F). Line a baking sheet with parchment paper.
On a floured work surface, roll out puff pastry into a 25-cm (10-inch) square and place on the baking sheet. Refrigerate while preparing toppings.
In a skillet, brown endives in 30 ml (2 tablespoons) of butter. Season with salt and pepper. Add apple juice and maple syrup and cook until juice is syrupy. Lightly blot endives with paper towel.
Spread cheese on pastry. Top with endives. Bake for 20 to 25 minutes or until pastry is golden brown. Right out of the oven, sprinkle with parsley.
Meanwhile, in a non-stick skillet over medium heat, brown sausage slices in remaining butter (15 ml/1 tablespoon) for about 1 minute on each side. Place sausage on pie. Cut into six portions and serve with lamb's lettuce or arugula.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.