Lentil and Vegetable Stew

• 250 g (8 oz) lentils, soaked overnight if necessary
• 2 medium potatoes, peeled and coarsely diced

Drain soaked lentils and simmer in a large pan in 1 pint water for about 20 minutes, or until nearly soft. Add the potatoes, courgettes, leeks and celery, season to taste with salt and pepper, and continue cooking for 15 to 20 minutes longer, or until the vegetables are cooked, adding more water if nec