Saute onions in oil until brown about 15 minutes. Add tomatoes and garlic, cover and simmer for 30 minutes. Add broth, butter, salt, pepper and sugar. Simmer for 1 hour. Crack eggs into individual wells in the soup. The soup should be fairly thick by this point. Cover and simmer until eggs are poached. Toast slices of bread. Sprinkle with parsley and serve with toasted bread.