Prepare the lentil, following the package instructions, don't overcook and let it cool.
Dice the mango and the bell pepper , cut the shallots in rings and crush the walnuts.
When the lentils are completely cool, mix with the other ingredients, drizzle with olive oil, lemon juice and pinch of salt and black pepper to your taste.
chop few leaves of parsley with the other ingredients. Mix well all the ingredients to allow all the flavors to integrate, cover with cling film and keep in the fridge.
For the vinaigrette, if you decide to add the smashed garlic and the dijon mustard will be better to prepare it in a separate container, mix well to integrate all the flavor, then add it to the whole salad.