Warm the oil in a large saucepan and add the chicken pieces, cooking them for five minutes or until lightly browned. Next, add the onion, garlic and celery and sauté until they start to become translucent.
Add the lentils, followed by the potatoes, stock, thyme and tarragon and bring to a steady boil for five minutes before simmering on a low heat for 20 minutes.
Add the lemon juice at the end and stir through. Chop or mash to desired texture.
Try experimenting with different types of lentils to vary the texture of this dish. Brown lentils have a lovely earthy taste and red lentils produce a mushier texture – which make them ideal for younger babies.