Season the lamb with salt and pepper. Brown the chunks in a large pot over medium heat until they develop color on all sides. Remove and set aside.
Add the onions, carrots, and celery to the pot. Cook for 5 minutes until the onions soften.
Stir in the 2 tablespoons of flour and cook for 1 minute. Return the lamb to the pot along with the potatoes, stock, thyme, and bay leaves.
Bring to a simmer, cover, and cook for 1 hour until the lamb is tender. Remove the bay leaves and taste for seasoning.
Heat the oven to 400°F. In a bowl, mix the 2 cups of flour, baking powder, and 1/2 teaspoon salt. Cut in the cold butter until the mixture looks like coarse crumbs.
Stir in the milk, parsley, and chives to form a soft dough. Drop spoonfuls of the dough over the hot stew.
Bake uncovered for 20 minutes until the scones are golden and risen.