In large pot, heat the oil over medium heat. Once the oil begins to shimmer, add the mushrooms and cook for about 5 minutes, or until most of their juices have been released.
Add the onions and carrots and cook for 4-5 minutes, or until onions are semi-translucent.
Add the garlic, herbs, black pepper, tomato paste, and soy sauce, and cook for 2-3 more minutes, until the herbs are fragrant.
Add the flour and stir until fully incorporated. Add the stock and stir until mostly absorbed.
Add the potatoes, tinned pearl barley and chopped swede and bring to a boil. Reduce the heat to medium-low and simmer for 45 minutes, stirring occasionally, until the potatoes are tender and the stew has thickened.Remove bay leaves once the vegetables have softened slightly. Make the scones by placing the flour and salt in a bowl. Rub in the fat with your finger tips. Stir in cheese reserving a little for the top. Add enough milk to make a stiff dough. Knead gently. Flatten with the heel of your hand into a circle- 1.5cms deep. Cut into 8 segments. glaze with some left over milk and scatter over the left over cheese.
Arrange segments on top of the simmering casserole and cook uncovered for 15 mins in a hot oven[220c, 425f, gas mark 7 until golden brown.