Rub the lamb roast all over with olive oil. Make 10 small slits all over the roast. Insert the bacon and garlic cloves into the slits. Season with salt and pepper. Place the roast in a roasting pan and add the stock and cover. Place in the oven and slow roast for 3 hours, or until very, very tender. Remove the lamb from the oven and cut into 2-inch pieces. Set aside.
In a large pot, add the butter and melt. Stir in the flour and let cook for 3 minutes. Add the onion and saute until soft, about 5 minutes. Add the carrots and the celery and saute for another 10 minutes. Slowly whisk in the stock that the lamb was cooked in. Add the reserved lamb. Bring to a simmer. Season with salt and pepper.
For the dumplings: In a large bowl, combine the flour, baking soda and salt and mix well. In a small bowl, beat the eggs. Add the milk to the eggs. Add the egg mixture to the dry ingredients and mix well. Stir in the goat cheese and the herbs. Season with freshly ground black pepper. Have the stock boiling in a small saucepan. Using 2 tablespoons, drop the dumpling batter into the boiling stock. Cook for about 5 minutes, or until the dumplings float to the surface. Remove the dumplings from the stock and place on a plate.
To finish: Place the dumplings into the stew. Check for seasoning. Garnish with fresh marjoram.