Preheat the oven to 375°F (190°C). Place the garlic cloves on a parchment paper-lined baking pan, drizzle with olive oil. Roast for 17-19 minutes until tender and lightly golden.
While the garlic roasts, place the parsnips in a large pot and cover with water. Bring to a boil over high heat, then reduce to medium heat and cook for 20 minutes, until very tender when pierced with a fork.
Drain the cooked parsnips in a colander, discarding the water.
Transfer the parsnips to a food mixer or a food processor along with the roasted garlic. Add the plant-based milk, olive oil, and salt. Process until completely smooth, scraping down the sides as needed.
Optionally garnish with thyme sprigs, a drizzle of olive oil, and a sprinkle of coarse-ground black pepper before serving.
