Heat the oven to 220C/200C fan/gas Whisk the oil, gochujang, sesame seeds, soy and lime juice in a large bowl, seasoning lightly. Add the vegetables and toss to coat. Tip the vegetables onto a large rimmed baking tray lined with baking paper, arranging them into a single layer. Roast for 40-45 mins, rotating the tray once, until tender and golden. Serve scattered with spring onions and lime wedges to squeeze over.