Heat oil in skillet and add tomato paste and chopped onions. Cook until onions are tender.

Meanwhile, in a small saucepan, combine carrots, parsnips and potatoes. Cover with water and simmer until vegetables are tender. Drain.

Transfer half of the vegetables to an oiled baking dish and cover with half of the tomato mixture. Repeat layers.

Add vegetable stock. Add barley and Tabasco and dot the top with butter. Bake at 350 degrees for 1 hour and 20 minutes, or until liquid is absorbed.