Preheat the Oven:
Preheat your oven to 200°C (180°C fan) or 400°F. This high heat will help to roast the potatoes and onions to golden perfection.

Prepare the Vegetables:
Sweet Potatoes & Potatoes: Peel and cut both the sweet potatoes and regular potatoes into cubes of about 1-inch (2.5 cm) size. This ensures they cook evenly.
Red Onion: Slice the red onion into wedges. You can leave the skin on for extra caramelisation during roasting.

Roast the Vegetables:
On a large baking tray, arrange the sweet potatoes, regular potatoes, and red onion. Drizzle with 2 tablespoons of olive oil and season with salt and pepper. Toss everything around to ensure an even coating.
Roast the vegetables in the preheated oven for 30-35 minutes, turning once halfway through the cooking time. They should be golden, tender, and slightly crispy at the edges.

Make the Dressing:
While the vegetables are roasting, whisk together the dressing. In a small bowl, combine 2 tablespoons of olive oil, 1 tablespoon of balsamic vinegar, 1 teaspoon of Dijon mustard, 1 teaspoon of honey, and the minced garlic.
Season with a pinch of salt and pepper, then whisk until the dressing is smooth and well-combined.

Assemble the Salad:
Once the roasted potatoes and onion have slightly cooled (about 5 minutes), transfer them to a large bowl. Add in the crumbled feta cheese and chopped parsley or rocket.
Drizzle over the dressing and gently toss the ingredients together. The warmth of the roasted vegetables will help the dressing soak in and melt the feta slightly for extra flavour.

Serve:
Serve the salad while it’s still warm. It’s perfect as a side dish to grilled meats, or even on its own with some extra greens or a drizzle of extra dressing.