Unlike tossed greens, this salad is an easy side for guests to eat while standing.
To prepare marinade, combine first 12 ingredients in a medium saucepan; bring to a boil. Cook until reduced to 1 cup (about 12 minutes). Let cool; discard bay leaves and thyme.
To prepare vegetables, bring water and 1 tablespoon sea salt to a boil in a Dutch oven. Add cauliflower, carrot, and beans; cook 2 minutes. Add fennel, onion, and mushrooms; cook 3 minutes. Drain; rinse with cold water. Drain. Place vegetables in a large bowl. Pour marinade over vegetables; toss well to coat. Cover and chill 4 hours. Drain; sprinkle with parsley.