Heat oven to 220C/200C fan/gas 7 and line a baking tray with baking parchment. Put the squash on the baking tray, drizzle over the olive oil, scatter on the cumin seeds and season generously – use your hands to ensure each piece is evenly coated with oil and seasoning. Roast for 30-35 mins until the edges are caramelised, then remove from the oven and leave to cool.
Meanwhile, bring a large saucepan of water to the boil. Cook the rice for 20-25 mins or according to pack instructions, then strain and rinse well with cold water until all the starch is washed off and the rice is cold. Allow to drain well.
Put the cranberries, pomegranate seeds, hazelnuts, herbs, onion and rice in a large bowl and mix well. Make the dressing by combining all the ingredients in a bowl with a generous amount of seasoning to taste. Once the squash is completely cool, gently mix it into the bowl of other ingredients. Pour over the dressing, mix well and serve on a large platter with the feta crumbled over the top.