Preheat your oven to 325°F (165°C). Place the ham, cut-side down, in a large roasting pan. Pour 1 cup of water or apple cider into the bottom of the pan to create steam.
Cover the pan tightly with heavy-duty aluminum foil. Place it in the preheated oven to gently heat.
Bake for 12-15 minutes per pound, or until an instant-read thermometer inserted into the thickest part (avoiding the bone) reads 120°F. This will take approximately 1.5 to 2 hours for an 8-pound ham.
While the ham is warming, prepare the glaze. In a small saucepan over medium heat, combine the brown sugar, honey or maple syrup, Dijon mustard, apple cider vinegar, ground cloves, and cinnamon.
Bring the mixture to a simmer, whisking constantly until the sugar is completely dissolved and the glaze has thickened to the consistency of warm syrup, about 3-5 minutes. Set aside.
About 45 minutes before the ham is scheduled to finish its initial heating, prepare the carrots. In a large bowl, toss the scrubbed carrots with olive oil, fresh thyme sprigs, salt, and pepper until evenly coated.
Carefully remove the roasting pan from the oven. Remove the foil and arrange the seasoned carrots in a single layer around the base of the ham. Return the pan to the oven, uncovered, to continue roasting.
Once the ham's internal temperature reaches 120°F, increase the oven temperature to 400°F (200°C).
Brush about one-third of the prepared glaze all over the surface of the ham, working it between the slices.
Return the ham to the hot oven and bake for 10-15 minutes, until the glaze is bubbly and beginning to caramelize.
Remove the ham, brush with another third of the glaze, and return it to the oven for another 10-15 minutes.
Repeat one last time with the remaining glaze. The final internal temperature should reach 140°F, and the ham should have a deep, glossy, mahogany-colored crust.
Carefully transfer the glazed ham to a cutting board and tent it loosely with foil. Let it rest for at least 15-20 minutes before carving to allow juices to redistribute.
While the ham rests, check the carrots. If they are not yet tender and caramelized, return them to the oven for another 10 minutes. Serve the carved ham alongside the roasted carrots.