Preheat the oven to 375 degrees F and line a baking sheet with parchment paper.
In a large bowl, toss together the oil, parsnips, bell peppers and onions. Season with salt and pepper. Spread in an even layer on the prepared baking sheet.
Bake until the parsnips are browned and cooked through, about 30 minutes. Serve immediately.
Recipe courtesy of The Kitchen