Prep time: 15 minutes
Cooking time: 45 minutes
Put the lentils, the bouquet garni and a litre of water in a saucepan and bring to the boil. Cook for ten minutes and add a teaspoon of salt. Cook until al dente and take off the heat.
Meanwhile, heat the olive oil in a casserole and sauté the onions, carrot, celery and fennel for ten minutes. Add the garlic and squash and cook for another ten minutes. Add the spring green stalks, cook for another five minutes and add the leaves.
Strain the lentils, discarding the water, and add casserole with the bouquet garni, to the vegetables. Stir in the mustard, check the seasoning and cook for another few minutes, adding a little water to get it to the right texture.
Serving Size Serves 6