Preheat the oven to 425°F and line a baking sheet with parchment paper.

Place the parsnips on the baking sheet. Drizzle generously with olive oil and sprinkle with salt and pepper. Toss to coat and spread evenly on the baking sheet. Roast for 30 to 40 minutes, or until tender and browned around the edges.

In a large bowl, whisk together the olive oil, rosemary, and garlic. Add the parsnips and toss to coat. Add the gremolata and lemon juice and toss again. Season to taste and serve.