With the rack in the middle position, preheat the oven to 400°F (200°C). Line a baking sheet with a few layers of paper towel.
In a large skillet, bring all the ingredients to a boil. Season with salt and pepper. Cover and let simmer over low heat for 15 minutes or until the endives are tender. Check their tenderness by inserting a toothpick into the centre. If it slides in easily, the endives are cooked.
Meanwhile, in a small pot over medium heat, melt the butter. Whisk in the flour and cook for 1 minute. Whisk in the milk. Bring to a boil and let simmer gently for 2 minutes or just until the sauce has thickened. Add the nutmeg. Season with salt and pepper. Remove from the heat and cover.
With a slotted spoon, remove the endives from the cooking liquid. Drain on the paper towels. Cover with a cloth or paper towels and press lightly to extract as much liquid as possible. Discard the cooking liquid.
In an 11 x 8-inch (28 x 20 cm) baking dish, lay out the drained endives. Cover with the béchamel sauce and sprinkle with the cheese.
Cook in the oven for 20 minutes or until the cheese has melted and is slightly golden. Sprinkle with the bacon and chives. Let cool for 15 minutes before serving.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.