Glazed organic carrot, feta and red onion tart - British Organic Carrots

Ingredients

• 300 g British organic carrots, peeled and cut into batons
• 2 red onions, sliced
• 1 tbsp olive oil
• 2 sprigs rosemary
• 500 g pack puff pastry
• A little flour, for dusting
• 1 small egg, beaten with 1tbsp water
• 1 tbsp balsamic vinegar
• Salt and freshly ground black pepper
• 4 tbsp pesto sauce
• 100 g feta cheese
• Rosemary or thyme sprigs, to garnish