Step 1 Cut the carrots into thick coins, about ¼-inch. Break the cauliflower into small florets. Cut the fennel diagonally into slices, ¼- to ½-inch thick. Blanch the carrots, cauliflower, fennel and garlic in or steam over boiling salted water until the carrots deepen in color, about 2 minutes. Drain and shock in ice water to preserve the color and stop the cooking process. Dry well and place in a mixing bowl.
Step 2 Toast the caraway seeds in a small pot over medium heat until fragrant, 1 to 2 minutes, watching carefully to prevent burning. Coarsely grind or chop the caraway seeds and return to the pot. Stir in the lemon juice, harissa, olive oil, salt and ground caraway and bring to a good simmer.
Step 3Pour the hot dressing over vegetables and stir. Set aside to cool and marinate at least 2 hours. Taste and add additional salt, harissa or lemon as desired. May be held at room temperature up to 6 hours, and up to 5 days refrigerated.