Blue cheese, butternut & barley salad with maple walnuts

From : http://www.bbcgoodfood.com/recipes/blue-cheese-butternut-barley-salad-maple-walnuts

Ingredients

1 butternut squash, peeled and cut into large chunks, seeds reserved
2 red onions, each cut into quarters
3 garlic cloves, peeled and bashed
3½ tbsp extra-virgin olive oil
handful thyme sprigs, leaves stripped, plus extra to garnish
300g pearl barley
50g walnuts, roughly chopped
1½ tbsp maple syrup
1 tsp brown sugar
½ tsp chilli flakes
2 tsp balsamic vinegar
1 tsp Dijon mustard
100g baby spinach, shredded
140g blue cheese, thinly sliced

Method : 
1. Heat oven to 200C/180C fan/gas 6. Toss the squash, onions and garlic with 2 tbsp of the oil and some seasoning. Roast for 35-45 mins or until the vegetables crisp up in places – turning halfway through cooking and adding the thyme leaves. Remove from the oven and allow to cool, discarding the garlic. Cook the barley, following pack instructions, until al dente. Drain and cool.
2. Meanwhile, rinse the squash seeds, removing any flesh, and dry thoroughly. Put the walnuts and squash seeds in a frying pan and toast until golden brown. Add ½ tbsp oil, the maple syrup, sugar, chilli flakes and some salt. Let it bubble for a few mins, until the sugar has caramelised. Tip onto a tray, allow to cool, then bash into pieces. Make a dressing by mixing the balsamic, mustard, remaining oil and some seasoning.
3. Toss the squash and onions through the barley, followed by the spinach and dressing. Scatter over the cheese, nuts and some extra thyme sprigs to serve.