Be sure to use a cast-iron skillet for this recipe; it maintains heat and will result in beautifully caramelized honey and well-cooked brussels sprouts. If you’re in a hurry, don’t worry about separating their leaves—the dish will still taste great.
Preheat oven to 400°F. Cut sweet potato lengthwise into 1/2-inch-thick slabs. Place the 2 center-cut potato slabs on a cutting board; reserve remaining sweet potato pieces for another use. Score 1 side of each slab in an 1/8-inch-deep diamond pattern. Stir together ginger, 1 teaspoon salt, coriander, and fish pepper flakes in a small bowl. Rub mixture evenly on sweet potato slabs.
Heat a large cast-iron skillet over high until smoking, about 3 minutes. Add oil, and swirl to coat bottom of skillet. Add sweet potatoes, scored side down, and cook until bottoms are golden brown, about 1 minute. Flip and arrange brussels sprouts, cut sides down, in a single layer around sweet potatoes. Drizzle with 2 tablespoons honey; transfer skillet to preheated oven. Roast until sprouts are tender and cut sides are caramelized, 12 to 15 minutes. Remove sprouts from skillet, and sprinkle with 1/4 teaspoon salt. Return skillet to oven; roast at 400°F until sweet potatoes are tender, 5 to 8 minutes.
Meanwhile, carefully separate brussels sprouts leaves, trimming stem ends if needed. Set aside.
Remove skillet from oven, and drizzle sweet potatoes with remaining 1/4 cup honey. Tilt skillet, and baste sweet potatoes until honey caramelizes and sweet potatoes are glazed, 2 to 3 minutes. Transfer sweet potato steaks to serving plates. Sprinkle with remaining 1/4 teaspoon salt, and drizzle with remaining caramelized honey in skillet. Top with brussels sprout leaves.
You can call them "steaks" but they're still plain old 'taters. Think I'll stick to beef when referring to a dish as 'steaks'!