A simple but great tasting tart that will will keep you warm any night of the week. Made with red onions and ricotta, it's a feast for the eyes as well! Preheat the oven to gas 6, 200°C, fan 180°C. Place a baking sheet in the oven. Dice the bacon, then put the oil in a large frying pan over a high heat and cook until the bacon turns golden. Remove with a slotted spoon and set aside. Add garlic and onions to the pan, turn the heat down and cook for about 6-8 minutes until softened and just turning golden. Stir in half the thyme leaves. Unroll the puff pastry and keep it on the baking paper it comes wrapped in. Score a 1-1·5 cm (1?2-3?4in) border around the edge. Spread the ricotta over the middle of the tart inside the border. Spoon on the onion mixture. Scatter over the diced bacon. Transfer the tart, still on the baking paper, to the baking sheet in the oven. Bake for 15-20 minutes, until risen and golden. Remove from the oven and scatter with the remaining thyme. Serve with the green salad.