Preheat the oven to 200 degrees Celsius (400 degrees Fahrenheit)
Cut the carrots in half lengthwise and cut the red onion into wedges. Place both veggies on a baking tray and drizzle with olive oil and salt. Bake in the oven for approximately 20 minutes until the carrots are tender and the red onion has softened. Once cooked remove from the oven and allow to cool.
Whisk together all of the ingredients for the dressing. You may need to add more water to thin it out. Taste and add more red wine vinegar or tahini if desired.
Place the arugula in a salad bowl or serving platter and arrange the roasted vegetables over top. Sprinkle with the sunflower seeds, chopped fresh mint and feta. Drizzle the dressing over top just before serving and toss to combine.