Preheat and Prepare: Preheat your oven to 375°F (190°C). Grease a large baking dish and arrange the yam slices in a single layer.
Make the Candied Mixture: In a small saucepan, melt the butter over medium heat. Add the brown sugar, honey, cinnamon, nutmeg, and salt. Stir continuously until the sugar has dissolved, and the mixture is well combined.
Coat the Yams: Pour the candied mixture over the yams, ensuring they are evenly coated. Cover the dish with aluminum foil and bake for 30 minutes.
Prepare the Glaze: While the yams are baking, combine the balsamic vinegar, pomegranate juice, brown sugar, honey, and salt in a small saucepan. Bring to a boil, then reduce heat and simmer for about 15-20 minutes, or until the glaze has thickened and reduced by half.
Final Bake: Remove the foil from the yams and pour the balsamic-pomegranate glaze over them. Return to the oven and bake, uncovered, for an additional 15-20 minutes, or until the yams are tender and caramelized.
Serve: Transfer the yams to a serving dish and drizzle any remaining glaze over the top. Garnish with pomegranate seeds and fresh thyme for a pop of color and flavor.