Soak the lentils in water to cover overnight. Next morning, chop the bacon and fry till the fat runs, then add chopped onion, and soften without browning. Stir in the lentils and any water remaining, and simmer till soft, adding a little more water if necessary to prevent burning. When lentils are soft, put through a sieve. Put the jointed rabbit in a casserole with cider, herbs, salt and pepper. Cover and cook in a slow oven at 325°F, 170°C, gas mark 3 till rabbit is tender. Drain off the rabbit liquid and mix with the lentil purée. Pour over the rabbit and continue cooking for fifteen minutes.