Line a large cookie sheet with parchment paper.
Place cut tomatoes, olive oil, garlic, onion, leeks, Italian seasoning, granulated sugar, salt and pepper in a large mixing bowl.
Stir well to combine ingredients.
Place tomatoes cut-side-up on top of parchment paper-lined cookie sheet.
Spoon onion, leek and drippings from bowl over top of each tomato as evenly as possible.
Remove oregano leaves, thyme leaves and rosemary from stems and mince.
Sprinkle over top of tomatoes.
Snip chives and add as desired.
Bake at 300° for about 1 hour.
Increase heat to 375° and roast for about 30 more minutes until tomatoes char or brown slightly.
Remove from oven and place tomatoes and veggies in a large stock pot or Dutch oven, and heat to medium.
Add vegetable broth and heat to boiling.
Turn off heat.
Check seasonings.
Add more, if desired.
With an immersion blender, puree tomato mixture until smooth.
Ladle soup into individual bowls.
Garnish with fresh rosemary, thyme, oregano and chives, as desired.