1. Place a medium heavy-based saucepan onto a medium heat and add in a splash of oil. Once the oil is hot, add in the sliced red onions and fry for 5 minutes or until beginning to caramelise, stirring occasionally. Add in the red wine vinegar and sugar then reduce heat to low and continue to cook until onions are completely softened, and the liquid has reduced to a sticky consistency (about 15 minutes). Remove from the heat and allow to cool.
2. Next make the pesto by adding the watercress, hazelnuts and garlic to a food processor with the olive oil. Blend for a couple of minutes then remove the lid and scrape down the sides and pulse a few times to ensure no big chunks are missed. Season to taste then set the pesto aside.
3. Place the broccoli florets into a bowl and drizzle with a little olive oil. Add a pinch of salt and pepper then toss to coat evenly.
4. Preheat your oven to 200°C. Take your pastry sheet and cut it into 4 equal rectangles. Place the rectangles on a baking tray. Spread the pesto thickly onto the pastries, leaving a 1cm border around the edge. Take a spoon and scatter the red onion mixture over the top evenly. Dot with the broccoli florets then put the baking tray into the oven. Bake for 10-15 minutes or until the pastry around the edges is risen and golden.
5. While the tarts cook, prepare the tomatoes. Use a pair of scissors to snip them into four equal sized portions, keeping as many tomatoes attached to the vine as possible. Place onto a baking tray, drizzle with olive oil and season with a little salt and pepper. Place into the oven with the tarts for the last eight minutes of cooking.
6. Finally remove your tarts and tomatoes from the oven and serve hot. For a different variation why not try swapping the broccoli for asparagus, kale or green beans.
Our thanks to www.watercress.co.uk for providing this recipe
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