Preheat the oven to 375°. In a large bowl, toss the fennel with the olive oil and herbes de Provence and season with salt and pepper. Scrape the fennel onto a large rimmed baking sheet and roast for about 30 minutes, until beginning to brown. Toss the fennel. Increase the oven temperature to 425° and roast for about 15 minutes longer, until golden and tender. Transfer to plates and serve.