Preheat your oven to 375°F (190°C). Spread peeled and chopped parsnips and sliced apples evenly on a baking sheet, then drizzle with olive oil. Toss gently to coat everything evenly.
Place the baking sheet in the oven and roast for about 35-40 minutes, until the parsnips are golden and tender, and the apples are caramelized and soft. The kitchen will fill with a sweet, toasty aroma.
Meanwhile, sauté the chopped onion in a little olive oil in a pot over medium heat until it becomes translucent and fragrant, about 5 minutes. This adds a subtle sweetness and depth to the soup base.
Once the roasted parsnips and apples are ready, add them to the pot with the sautéed onion. Pour in the vegetable broth and bring the mixture to a gentle simmer for 10 minutes, allowing the flavors to meld.
Puree the mixture using an immersion blender directly in the pot until smooth and velvety. Alternatively, carefully transfer the mixture to a blender and blend in batches, then return to the pot.
Add a splash of apple cider vinegar to brighten the flavor and season with salt and pepper to taste. Stir well and taste for balance, adjusting seasoning as needed.
Reheat the soup gently if needed, then ladle into bowls. Serve hot, garnished with a drizzle of good olive oil or fresh herbs if desired for a beautiful presentation.
