Healthier Rhubarb Crumble - Slow Cooker

SERVES 6: 1. Lightly oil a 900ml (1 and a half pint) heatproof dish. Place an upturned saucer in the base of the dish and pour cold water 2.5cm (1") around it. Switch the slow cooker to high. 2. Put the flour in a large bowl and cut the butter into small chunks. Add this to the flour and rub them together with your fingers until the mix looks like fine breadcrumbs. You may also blend them together in a food processor. 3. Stir in the sesame seeds, cinnamon, rolled oats and demarara sugar. Mix well and set aside. 4. To prepare the rhubarb, remove the thick ends of the stalks and cut diagonally into 1" (2.5cm) chunks. Wash thoroughly and pat dry with a clean cloth. Place the rhubarb in the serving dish. 5. Sprinkle the caster sugar on to the rhubarb and top with the set aside crumb mixture. Level the top so all the fruit is covered and pressed down firmly. If you want it a bit sweeter, sprinkle a little more caster sugar on top. 6. Cover with a lightly oiled sheet of tin foil, and then place in the slow cooker. Pour sufficient boiling water around - enough to come halfway up the side of the dish. 7. Cook for 4 to 6 hours, until the fruit is tender. If you prefer a crisp and crunchy topping, remove the tin foil for the last 30 minutes of the cooking time. 8. Serving with hot custard, cream or ice cream would be perfect.