Peel and finely dice the onion and garlic. Heat 2 tablespoons of oil in a saucepan. Fry the onion and garlic over a low heat until transparent. Add the barley and sauté briefly.
Season with salt and pepper. Add broth and wine bit by bit, stirring from time to time. Add the next portion of liquid only after the barley has absorbed the liquid. Cook for about 30 minutes in total
Wash, clean and quarter the tomatoes. Clean and wash spring onions and cut into fine rings. Grate parmesan. Cut butter into flakes. Mix all ingredients together. Arrange on plates