Toss the lamb chunks with the flour, salt, and pepper until lightly coated.
Heat the olive oil in a large skillet over medium-high heat. Brown the lamb in batches, then transfer it to the slow cooker.
Add the onion and garlic to the same skillet and cook for two minutes until they start to soften.
Place the carrots, parsnips, and potatoes into the slow cooker with the lamb.
Pour the broth over the meat and vegetables, then add the thyme sprigs.
Cover and cook on low for 7 to 8 hours until the lamb is fork-tender.
Remove the thyme stems before serving and sprinkle the chopped parsley over each bowl.