1.Preheat oven to 200°C/400°F.
2.Cut rhubarb into 8cm (3¼in) lengths. Place in a flameproof roasting pan, cover with foil; roast for 20 minutes or until rhubarb is soft but still holds its shape. Carefully transfer to a plate, leaving one piece of rhubarb in the pan. Leave the oven on for making sweet dukkah.
3.Add the 2 tablespoons of water to rhubarb in pan; mash until mixture breaks up. Cook over low-medium heat, stirring, for 1 minute or until rhubarb breaks down into a sauce consistency. Remove from heat; cover to keep warm.
4.Make sweet dukkah: Place nuts and seeds on an oven tray lined with baking paper; roast for 5 minutes. Crush coarsely with a mortar and pestle; cool. Place sugar and spices in a small bowl, add nut mixture; mix well.
5.Meanwhile, whisk milk, coconut milk, honey and the extra water in a medium saucepan; bring to the boil. Reduce heat to low, slowly add polenta; cook, whisking constantly, for 2 minutes or until thick.
6.Divide polenta evenly among four bowls; top evenly with rhubarb and rhubarb sauce; Sprinkle with dukkah to serve.
- The rhubarb can be cooked the day before; store in an airtight container, large enough so the rhubarb holds its shape, in the fridge.
* Rhubarb cooking time may vary according to thickness and ripeness of the rhubarb, so check after 15 minutes, then continue to cook if necessary.