Preheat the oven to 400. Toss the carrots with the olive oil, 1 tablespoon chervil/parsley, and salt and pepper. Chantenays are sweet carrots, so be generous with the salt. Arrange the carrots in a single layer on a baking sheet and roast for 20 minutes. While still hot, toss with the remaining tablespoon of chervil/parsley, the butter, and a bit more salt and pepper. Serve!