In our garden, carrots start showing up in November, and we love to showcase them on menus all through the fall and winter. The next time you’re buying carrots at the farmers’ market, and the vendor asks if you want the tops left on, say yes! You might think of them as scraps for the compost bin, but like most root-vegetable greens, they’re filled with flavor and nutrients. They taste like a cross between a soft herb (like chervil or parsley) and a carrot, and a chunky pesto like this one is a perfect way to show off their flavor, especially when you use it to accent the simply roasted carrots they grew with in the first place. Carrot tops can sometimes be a bit tough and bitter. For this recipe, it’s best to use carrots with very tender greens from your garden or the farmers’ market.
To roast the carrots: Preheat the oven to 450°F convection (475°F conventional). Place a sheet pan in the oven to preheat for 5 minutes.
Rinse the carrots and carrot tops with cool running water. Trim off the tops and reserve 2 cups firmly packed tops. Trim off the root ends of the carrots. In a medium bowl, combine the carrots, 2 tablespoons of the oil, and the kosher salt and toss to coat evenly.
Remove the hot sheet pan from the oven and pour the carrots onto it in an even layer. Roast for 7 minutes, stir, and roast for about 7 minutes longer, until the carrots are tender but not mushy.
To make the pesto: While the carrots are roasting, in a food processor, combine the reserved carrot tops, tarragon, lemon zest and juice, and a small pinch of Maldon salt and pulse a few times, stopping and scraping down the sides of the bowl between pulses. Add the cheese and pulse until the greens are just chopped and the cheese is mixed. Add the hazelnuts and pulse until all of the nut pieces are no larger than a petite pea. The pesto should have a textured consistency, with all of its ingredients visible. Measure 3/4 cup of the pesto for dressing the carrots. The remaining pesto will keep in an airtight container in the refrigerator for up to 1 week.
To serve: Transfer the 3/4 cup pesto to a medium bowl, add the remaining 1/2 cup oil, and stir to mix well. Add the hot carrots to the mixing bowl and toss well with the pesto mixture. Taste and adjust the seasoning with Maldon salt if needed. Transfer the carrot mixture to a serving platter and serve immediately.