Trim 6 medium artichokes, leaving the stems intact. Halve lengthwise. Cook 2 each sliced carrots, celery stalks and leeks in a pot with 1/4 cup olive oil over medium heat until tender, about 12 minutes. Add 3 sliced garlic cloves; cook 2 more minutes. Add the artichokes in a single layer; add 2 teaspoons salt, 2 bay leaves, 3 thyme sprigs, 1 rosemary sprig, 1 1/2 cups white wine, and water to cover. Lay a round of parchment paper on the artichokes and simmer until tender, 25 to 30 minutes. Let cool in the liquid.
Photograph by Kang Kim