Preheat your oven to 400°F (200°C). Toss the peeled and chunked parsnips with olive oil, salt, and pepper. Spread them out on a baking sheet and roast for 25-30 minutes until they are golden and caramelized around the edges.
While the parsnips roast, heat a splash of olive oil in a large pot over medium heat. Add the chopped onion and sauté until translucent and fragrant, about 5-7 minutes. Add the minced garlic and cook for another minute until it releases a nutty aroma.
Once the parsnips are roasted and tender, add them to the pot with the sautéed onions and garlic. Pour in the vegetable broth and bring the mixture to a gentle simmer. Let it simmer uncovered for 10 minutes to allow flavors to meld.
Blend the soup until smooth using an immersion blender directly in the pot, or transfer carefully to a blender in batches. Puree until the mixture is silky and uniform, with no lumps. Return to heat if needed.
Taste the soup and adjust the seasoning with more salt and pepper as needed. Stir in a teaspoon of toasted sesame oil to add a nutty aroma and flavor, then remove from heat.
Spoon the hot soup into bowls and garnish with a drizzle of sesame oil or fresh herbs if desired. Serve immediately to enjoy the warm, creamy texture with a subtle nutty finish.
