Preheat the oven to 300°F (150°C).

Cut the pork belly into 2-inch cubes and place in a Dutch oven or oven-safe pot.

Add the duck fat, minced garlic, and thyme leaves to the pot.

Season with salt and pepper.

Cover the pot and place in the preheated oven.

Cook for 4 hours, until the pork is very tender and easily shreds.

Remove the pot from the oven and let it cool slightly.

Using two forks, shred the cooked pork in the pot, mixing it with the rendered fat.

Transfer the pork and fat mixture to jars or ramekins.

Press down lightly to remove any air pockets.

Cover and refrigerate for at least 2 hours, or until chilled and set.

Serve the pork rillettes on toasted bread or crackers, garnished with fresh herbs if desired.