Preheat oven to 400˚F. Line two sheet pans with parchment paper or foil. Drain tomatoes well, reserving juice. Set juice aside.

Cut tomatoes in half and place on one of the prepared pans with cut side up. Drizzle tomatoes with 2 tablespoon olive oil. Sprinkle with sea salt and freshly ground black pepper.

Cut celery into 2-3-inch pieces. Cut onions in half then each half into 4 wedges. Cut each shallot in half. Place all veggies on second pan and drizzle with 1 tablespoon olive oil. Sprinkle with ½ teaspoon sea salt and a generous grind of black pepper. Stir to coat veggies with oil. (I like to do this with my hands.)

Cut ¼ inch off top of garlic. Place, cut side down, in a small, oven-safe bowl. Drizzle with 2 teaspoons of olive oil and cover with foil. Place bowl on sheet pan with onion mixture.

Place both pans in the oven and roast for 30 minutes. Remove from oven. Turn tomatoes so that cut side now faces down. Stir onion mixture and return both pans to oven.

Roast onion mixture another 15 minutes, then remove from oven. Tomatoes should be roasted another 30 minutes for a total of 1 hour.

Cool slightly, then squeeze garlic bulbs to release individual cloves.Transfer garlic and contents of both pans to a large Dutch oven. Add reserved tomato juice, chicken broth and pesto, stir well. Add oregano, basil, anchovies and brown sugar and bring to a boil. Reduce to a simmer and cook for 15 minutes, then puree with an immersion blender to a regular blender.**

To serve, combine Greek yogurt and milk, stir until smooth. Ladle soup into bowls and drizzle with a bit of Greek yogurt mixture and pesto. Serve hot.