Defrost the spinach and squeeze to take the excess water.
Cut the butternut squash in 4 big pieces and roast it until soft. Leave to cool down, peel and slice it and reserve.
Heat the coconut oil in a large saucepan and gently fry the onion and garlic for 4-5 minutes.
Stir the drained lentils, bay leaf, tomatoes, tomato puree, herbs, stock and water into the onions. Bring to the boil and simmer covered for 10 minutes. Season to taste and remove the bay leaves.
Grease a roasting pan with coconut oil.
Arrange a layer of very thinly sliced butternut squash on the bottom, then place a layer of spinach, then spoon over a layer of lentil mixture and sprinkle part of the grated cheese. Make another layer in the same sequence. Finish with the sauce in the top layer sprinkled with the rest of the cheese.
Bake for 30 minutes or until the cheese on the top is brown and the sauce bubbling.