Mix the squash and onions with the oil, salt and pepper, place on a baking tray lined with baking paper.
Approx. 45 mins. in the centre of an oven preheated to 200°C. Combine the lemon juice, vinegar, oil, honey and chilli flakes in a bowl. Add the squash, mix.
Bring the sugar and water to the boil in a wide pan without stirring. Reduce the heat and simmer, swirling the pan occasionally until a light brown caramel has formed. Add the walnuts, pumpkin seeds and fleur de sel, mix, transfer to a sheet of baking paper, leave to cool. Break the nut brittle into pieces.
Serve the squash salad with the feta, pomegranate seeds, parsley and mint. Scatter the nut brittle on top.