1. Preheat Oven and Prepare Vegetables: Preheat your oven to 400°F (200°C). Line a large baking sheet, or two if necessary, with parchment paper for easier cleanup. This also prevents the tomatoes from sticking and ensures even roasting.

2. Roast the Vegetables: On the prepared baking sheet(s), combine the halved/quartered tomatoes, quartered onion, peeled garlic cloves, chopped carrots, and chopped celery. Drizzle generously with 1/4 cup of extra virgin olive oil. Season with sea salt, black pepper, and dried oregano (if using). Toss everything together with your hands to ensure all the vegetables are evenly coated with oil and seasonings. Spread the vegetables in a single layer on the baking sheet. It’s important not to overcrowd the pan, as this will cause the vegetables to steam rather than roast. Use two baking sheets if your vegetables don’t fit comfortably in one layer.

3. Roasting Process: Place the baking sheet(s) in the preheated oven and roast for 40-50 minutes. The vegetables should be tender, slightly charred, and caramelized around the edges. The tomatoes should be soft and their skins slightly blistered. The aroma filling your kitchen at this point will be incredible! About halfway through the roasting time, you can give the vegetables a gentle stir or shake the pan to promote even cooking.

4. Cool Slightly: Once roasted, remove the baking sheet(s) from the oven and let the vegetables cool for about 10-15 minutes. This makes them easier to handle and safer for blending, especially if you’re not using an immersion blender. Don’t discard any delicious juices that have accumulated on the baking sheet; these are packed with flavor.

5. Blend the Soup: Transfer the roasted vegetables, along with any juices from the baking sheet, to a high-powered blender. If you have a smaller blender, you may need to do this in batches. Add the packed fresh basil leaves to the blender. If you opted to use a pinch of sugar to balance acidity, you can add it now.

6. Achieve Smoothness: Secure the blender lid tightly. If blending hot vegetables, remove the center cap from the lid and cover the opening with a folded kitchen towel to allow steam to escape and prevent pressure buildup. Start blending on low speed, then gradually increase to high. Blend until the soup is completely smooth and velvety. This might take 1-2 minutes depending on your blender. For an ultra-smooth soup, you can strain it through a fine-mesh sieve after blending, but this is an optional step.

7. Simmer the Soup: Pour the blended soup into a large pot or Dutch oven. Stir in the vegetable broth. Bring the soup to a gentle simmer over medium heat. Be careful not to let it boil vigorously. Cook for about 10-15 minutes, stirring occasionally, to allow the flavors to meld together. Taste the soup and adjust seasonings if necessary – you might need a bit more salt or pepper.

8. Add Cream (Optional): If you desire a creamier soup, reduce the heat to low and stir in the heavy cream or full-fat coconut milk. Stir until well combined and heated through. Do not let the soup boil after adding the cream, as it could curdle (especially dairy cream).

9. Serve Warm: Ladle the hot Roasted Tomato Basil Soup into bowls. Garnish with fresh basil leaves, a swirl of extra cream or olive oil, homemade croutons, or a sprinkle of black pepper. Enjoy this delicious homemade soup immediately.