With the rack in the middle position, preheat the oven to 200 °C (400 °F).
On a baking sheet, toss onions with 30 ml (2 tablespoons) of oil. Bake for about 30 minutes or until onions are soft and golden brown. Set aside.
Meanwhile, in a pot of boiling water, cook lentils for about 25 minutes or until tender but still whole. Rinse under cold running water and drain. Spread onto the baking sheet with roasted onions. Let cool on the baking sheet.
In a bowl, combine remaining oil (30 ml / 2 tablespoons) with balsamic vinegar. Drizzle dressing over lentil mixture and add 30 ml (2 tablespoons) of parsley. Season with salt and pepper. Toss well. Place on a large serving platter. Spread asparagus over salad.
In the vinaigrette bowl, combine chicken, remaining parsley (15 ml/1 tablespoon) and lemon juice. Spread on top of vegetables. Adjust seasoning. Serve warm or cold.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.