Caramelised Red Onion and Blue Cheese Tart Recipe | Abel & Cole

Ingredients

• 4 good-sized red onions, thinly sliced
• A splash of olive oil
• A pinch of sea salt
• ½ tsp freshly ground black pepper
• 1 bay leaf (optional)
• 5 tbsp red wine
• 2 tbsp balsamic vinegar
• ¼ tsp soy sauce
• 1 tsp butter
• 150g blue cheese (Stilton works a treat)
• A good pinch of freshly chopped rosemary leaves
• A handful of toasted walnuts
• About 200g all-butter puff pastry:
• 200g plain white flour
• 1/4 tsp baking powder
• 100g unsalted butter, fridge cold
• 6-8 tbsp cold water