Preheat oven to 375 degrees.  Slice tomatoes in half and place on an oiled pan, cut side down.  Score the skin on the top of tomatoes.  Place quartered onions on pan.  Cut top 1/3 of garlic head off, then wrap the bottom in foil (leaving top open) and drizzle with olive oil. Place head of garlic on pan and place in oven.  Roast for 30-40 minutes, or until tomatoes are slightly charred and garlic is soft.

In a soup pot, add 1 TBS olive oil, then roasted onions, tomatoes, and squeeze out bulbs of garlic.  Add Worcestershire sauce and tomato paste, and cook until juice is almost boiling.  Pour in canned tomatoes, and blend using an immersion blender.  Add in bay leaves, thyme, oregano, and chicken stock.  Bring to a boil then reduce to a simmer and cook for 45 minutes to 1 hour, or until thickened.  Adjust for salt and pepper and sugar.  Add 1-2 tsp flour if necessary to thicken.  Stir in fresh Italian parsley and cream, then remove from heat.  Garnish each bowl with fresh basil, or swirl in heavy cream for garnishing.  Serve with grilled cheese sandwiches.