1: Finely grate the lemon zest and set it aside. Cut the lemon in half.

2: Using kitchen scissors, cut the prickly tips off the artichoke leaves. Trim 1/8 inch off the end of the artichoke stems. (The rest of the stem is edible.) Using a chef’s knife, cut each artichoke in half lengthwise. Cut the top half-inch off each artichoke half and discard. Using a melon baller or spoon, scrape out and discard the “choke” (the clump of fibers just above the heart). Rub the cut parts of the artichokes with the cut sides of the lemon to keep the artichokes from browning.

3: Bring 1 gallon of water with 4 teaspoons of salt to a boil in a large stockpot.

4: Place the artichokes in the boiling water and cook until just tender, 10 to 15 minutes, or as needed. Use a metal skewer to test for doneness: It should pierce the artichoke with just a little resistance. Do not overcook: The artichokes should remain firm. Drain the artichokes in a colander, running cold water over them until they are cool. Position the artichokes cut side down on a wire rack over a rimmed sheet pan and drain well. The artichokes can be cooked ahead to this stage and refrigerated for up to 24 hours.

5: Set up your grill for direct grilling and heat to high. If using a charcoal grill, place hardwood chunks or chips on the coals. If using a gas grill, place a few wood chunks in the smoker box or directly over the burners under the grate. If using a wood-burning grill, do nothing more than light it: Don’t let the flames die down completely—flames mean smoke and smoke means flavor. Brush or scrape the grill grate clean and oil it well.

6: Stir the lemon zest and garlic into the olive oil. Brush the cut sides of the artichokes with the lemon-garlic oil and dab more oil between and over the leaves. Season with salt and pepper. Arrange the artichoke halves, cut sides down, on the grill, running diagonal to the bars of the grate. Grill for about 2 minutes or so, then give each artichoke a quarter turn to lay on a crosshatch of grill marks. Grill until the cut side is darkly browned, about 2 minutes more. Baste the tops of the artichokes with the oil, dabbing it under the leaves.

7: When the cut sides are nicely browned, turn the artichokes over and grill the leaf side, again basting with the lemon-garlic oil. The artichokes are ready when sizzling hot and browned on both sides and easy to pierce with a fork, another 2 to 4 minutes, 6 to 8 minutes in all. Transfer the artichokes to a platter or plates, cut sides up. Spoon some of the Harissa Mayonnaise into the hollow part of the artichokes. Spoon a dab of straight harissa in the center and sprinkle with the chives (if using). Serve the remaining Harissa Mayonnaise on the side.