Rinse the pork under running water for 1 minute and pat dry. Score the rind in a diamond pattern with a sharp knife. Season all sides with salt and pepper.
Preheat the oven to 220°C (428°F). Heat the lard in a roasting pan on the stovetop over medium-high heat. Place the pork skin-side down and sear for 5 minutes. Add 250 ml water and transfer to the preheated oven for 15 minutes.
Reduce the oven temperature to 180°C (356°F). Flip the pork skin-side up and roast for 2 hours, basting with hot water every 30 minutes. Mince the garlic clove and combine with soft butter and caraway seeds. With 30 minutes remaining, brush the crust with the garlic-butter mixture. For the final 20 minutes, switch to broiler (top heat) and pour the dark beer over the pork. Check that the pork reaches an internal temperature of 63°C (145°F).
Remove from oven and let rest for 10 minutes before slicing.