- Preheat oven to 200˚C and line a tray with baking paper.
- Spread sweet potato on the tray evenly, drizzle with olive oil and sprinkle with salt. Place in the oven and roast for 20 minutes.
- While the sweet potatoes are in the oven, cook pasta according to packet instructions (around 7 minutes). Drain the pasta and place into a large serving bowl.
- While pasta is cooking, sauté the diced onion for the dressing over medium heat in a pan with the extra olive oil, until it has changed to a golden brown colour. Set aside to cool.
- Once the sweet potatoes have roasted for 20 minutes, remove the tray from the oven. Turn the pieces over and add the tomatoes to the tray to roast for another 10-15 minutes.**
- Meanwhile place the walnuts on a separate oven tray and roast for up to 10 minutes, tossing occasionally.
- Once the sweet potatoes and tomatoes are both ready, add them to pasta along with baby spinach. Mix to combine.
- Make the dressing: combine the olive oil with apple cider vinegar and caramelised onions in a jar, and shake well.
- Pour dressing over the salad, add the roasted walnuts (broken up if desired) and crumble over with feta cheese.
- Finish with freshly ground black pepper and serve either warm or cold.
** Sweet potato cooking time may vary, depending on your oven. Chop them into similar sized cubes to ensure they cook evenly.