Have a bowl of ice ready. Cook carrots in salted boiling water until color brightens and carrots are slightly flexible, 2 minutes. Drain and immediately toss carrots with ice and cold water to stop the cooking process and preserve their color. Drain and pat carrots dry. Carrots may be prepared a day ahead to this point and refrigerated covered.
Heat grill or grill pan to medium or medium-high. Toss carrots with about 1 tablespoon olive oil, about ½ teaspoon salt, and any other ground spices. Spread carrots on hot grill surface and grill until the top surface looks a little blistered and the underside has nice grill marks, but are not burnt, about 4 minutes (adjust grill heat accordingly to slow down or speed up cooking time as needed). Turn and grill second side.
Place carrots on a serving platter and drizzle with a little more olive oil if you’d like and additional salt and seasonings. Zest lemon over carrots, if using, and add a nice squeeze of the juice. Scatter herbs over all.