Combine the tomatoes and carrots and bell pepper on a sheet pan and drizzle with 2 tablespoons of olive oil and the balsamic vinegar. Sprinkle with the Italian seasoning, garlic salt, sugar and pepper. Toss with your hands to evenly distribute the oil and seasonings. Place the 6 cloves of garlic on a small piece of foil. Drizzle lightly with olive oil and bring up the edges of the foil to make a tightly sealed packet. Push some of the veggies away from the center of the pan to make a place for the garlic packet and nestle into place.
Place the pan in the preheated oven and roast for 15 minutes. Shake the pan gently to rotate the carrots and tomatoes. Flip the pepper pieces to the opposite side. Roast for another 20-25 minutes or until most of the juice from the tomatoes has evaporated. Remove from the oven.
While the veggies are roasting, heat the 1 tablespoon of butter in a large soup or stockpot over medium heat. Add the chopped onion and cook for 3-4 minutes, stirring occasionally, until softened and translucent. Add the tomato paste and cook for another 2-3 minutes until the tomato paste deepens in color.
Add the chicken broth, potatoes and salt. Increase the heat and bring to a medium boil. Cover and cook for 20 minutes until potatoes are nice and soft.
Add the roasted veggies (just squeeze the garlic cloves out of their skins) and fresh basil leaves and blend until smooth, using an immersion blender. You can also transfer the mixture to a regular blender, add the roasted veggies and blend until smooth. (If using a regular blender, be sure to leave the center cap of the cover off and cover the opening with a sieve, kitchen towel or several thicknesses of paper towels to prevent heat build-up and possible explosion.)
Add 2-4 tablespoons of cream (optional) and stir to blend. Taste and season with more kosher salt, if needed. If you prefer a thinner soup, add a bit more chicken broth.
Serve the soup bowls, garnished with halved cherry or grape tomatoes and/or a drizzle of cream or balsamic vinegar and fresh basil leaves. Refrigerate any leftovers and enjoy within 3-4 days or freeze for a delicious dinner on a busy day!
See Café Tips above in the post for more detailed instructions and tips to ensure success with this recipe.