Begin by preheating your oven to 220°C (200°C for fan ovens), gas mark 7, or 425°F.
In a roasting tray, arrange the beetroot cubes on one side and the butternut squash cubes on the other.
Drizzle 2 tablespoons of olive oil over the vegetables and season with a sprinkle of salt and pepper.
Gently toss the beetroot and butternut squash in the oil, being careful not to mix them to avoid staining the squash.
Place the tray in the preheated oven and roast for 10 minutes.
After this time, take the tray out and give the vegetables a turn in the oil, again being cautious not to discolor the butternut squash.
Return the tray to the oven for an additional 10-15 minutes, or until both the beetroot and butternut squash are tender and have a light golden color.
While the vegetables are roasting, prepare a simple balsamic dressing.
Combine all the dressing ingredients in a clean jar, seal it with a lid, and shake vigorously until well blended.
On a separate tray, spread out the walnut halves and roast them in the oven alongside the vegetables for about 3 minutes.
Remove the tray when done.
Once the roasted vegetables are cooked to your preference, take them out of the oven to assemble your salad.
Divide the salad greens among four plates, then add an equal amount of the roasted butternut squash and beetroot on top.
Drizzle a spoonful of the balsamic dressing over each plate and sprinkle with crumbled feta cheese.
Finish by scattering the roasted walnuts on top.
Serve the salad immediately as a main course, accompanied by pitas or flatbreads.
Offer the remaining dressing on the side for guests to add more as desired.