How to Make It
Peel ginger, and grate to equal 1 teaspoon; set grated ginger aside. Slice remaining ginger. Combine sliced ginger, 6 cups water, star anise (if using), and 1 tablespoon salt in a large Dutch oven. Cover and bring to a boil over high. Reduce heat to medium-low; cover and simmer 10 minutes. Remove and discard solids. Add carrots to Dutch oven; simmer 4 minutes. Increase heat to high. Add bok choy; cook until carrots are tender and bok choy is bright green and crisp-tender, 1 to 2 minutes. Using a slotted spoon, transfer vegetables to a colander; rinse under cold water until cool. Drain.
Add wine to Dutch oven. Bring to a boil. Reduce heat to medium (only tiny bubbles should appear, and water temperature should be around 160°F). Add fish; cook, without stirring, until fish just flakes with a fork, 6 to 8 minutes. Using a slotted spoon, remove fish from liquid. Sprinkle fish with 1/2 teaspoon salt.
Heat grated ginger and butter in a large skillet over medium 30 seconds. Stir in carrots, bok choy, and remaining 1/4 teaspoon salt. Cook, stirring constantly, until heated through, 2 to 3 minutes. Place vegetables on a serving platter. Top with fish, orange segments, and parsley. Garnish with pepper.