September 22, 2011 - 09:05 BST hellomagazine.com A recipe for Cheddar, red onion and rosemary tart to celebrate National Cheese Week Ingredients (Serves 4) 1 ready-rolled puff pastry sheet, thawed 15g (1/2oz) butter 1 tablespoon olive oil 2 large red onions, sliced 1 rounded teaspoon light or dark muscovado sugar salt and freshly ground black pepper 1 teaspoon dried mixed Italian herbs 75g (3oz) mature Cheddar cheese, grated a few sprigs fresh rosemary or thyme Method Preheat the oven to 220°C / 425°F / Gas Mark 7. Lightly grease a baking sheet and lay the puff pastry sheet on top. Heat the butter and oil in a frying pan and add the red onions. Cook, stirring occasionally for 5 minutes, then add the sugar and cook for another few minutes until the onions are very soft and caramelised. Season with salt and pepper and add the dried herbs. Cool for a few minutes. Spread the onions over the pastry sheet to within 2cm (3/4 inch) of the edges. Scatter the cheese on top, then add the rosemary or thyme sprigs. Transfer to the oven and bake for 12 - 15 minutes until puffed up and golden brown. Cool for a few moments, then slice and serve.