Rinse and drain the puy lentils, then transfer to a medium saucepan. Add the vegetable stock, bring to a boil, and simmer on low heat for 20 minutes.
Meanwhile, rinse and drain the rice, transfer to a medium saucepan and add a pinch of salt and hot water. Cover and bring to a boil, then simmer on low heat for 10 minutes.
In a large mixing bowl, combine the lentils, rice, borlotti beans, and celery. Season with salt and pepper, a squeeze of lemon juice and garnish with chopped parsley.
Notes
Prepare a few hours ahead of time for best results.*If using a good brand of borlotti beans, such as Cirio, do not drain as the liquid adds wonderful flavour.Store in the fridge for up to 2 days.Remove from the fridge 1 hour before serving.