Preheat your oven to 400°F.: The instant the oven heats up you will notice a warm, dry air that sets the scene for caramelization, which is essential for that roasted sweetness in Roasted Tomato Soup . Make sure the oven reaches the full temperature before you slide the pan in, because starting in a cold oven delays browning and can lead to steamed rather than roasted tomatoes . A common mistake is crowding the pan, so spread the tomatoes evenly to promote even charring and avoid soggy centers.
Add the tomatoes to a 9×13-inch baking pan, drizzle with 2 tbsp of the olive oil and then season with salt and pepper. Transfer the pan to the oven and bake for about 30 minutes or until the tomatoes start to char. Add the tomatoes with the skin on to a food processor or blender and 1 cup of the vegetable broth. Blend until tomatoes are smooth.: The air will fill with an intense, sweet tomato aroma as the skins blister and the fleshy parts darken, signaling concentrated flavors developing. When you see edges darkened and juices bubbling, the sugars have caramelized and the texture will be softer for blending. Keep an eye on the color rather than strict timing, because the exact minute depends on tomato size. If you wait too long, the tomatoes can become overly dry, so remove when they are richly colored with some char. Blending with 1 cup of vegetable broth helps the blades move and makes a silky puree, but be cautious of hot splatter; pulse to start, and hold a towel over the lid until pressure eases.
In a large Dutch oven or heavy soup pot, heat the remaining 2 tbsp of olive oil and melt the butter over medium heat. Add the onion and cook for about 5 minutes, or until onion is translucent. Stir in the garlic and cook for another 30 seconds until aromatic.: You will hear gentle sizzling and smell the sweetening onion aroma as it softens, which builds the savory foundation for the soup. The butter adds a glossy finish and helps carry flavors, while not browning keeps the base mild and sweet. Avoid high heat here because burnt garlic turns bitter quickly; lower the heat if things color too fast. Stirring occasionally ensures even cooking and prevents sticking.
Add the fresh basil, thyme and stir. Sprinkle the flour over the onion mixture and stir again. Cook for about 1 to 2 minutes to get rid of the raw flour taste. Stir in the remaining 1 cup of vegetable broth or whisk if necessary to remove any flour lumps. Next, pour the blended tomatoes and stir. Finally, stir in the brown sugar, smoked paprika, and if needed, season with salt and pepper.: The herbs release bright top notes that contrast the roasted tomatoes , and incorporating the flour here creates a roux-like body to give the soup a velvet texture. You will notice the mixture thicken slightly as the flour cooks; whisking while adding the remaining vegetable broth prevents lumps. Once the blended tomatoes go in, the pot will steam up and the aroma will turn rich and layered; taste for seasoning because the concentrated tomatoes may need that little touch of brown sugar or salt to round them out. A misstep is failing to cook the flour enough, leaving a raw starchy taste, so give it the full minute to two.
Let the soup simmer, while uncovered, for 20 – 30 minutes. Serve with grated parmesan cheese and toasted bread.: As the soup simmers gently you will see it thicken and the flavors meld, with the surface offering occasional small bubbles and a fragrant steam full of roasted tomato and herb notes. Simmering uncovered concentrates flavors and allows any excess liquid to evaporate, improving texture. Stir periodically to prevent a skin from forming and to check for seasoning. If the soup seems too thick, add a splash more vegetable broth . Avoid a rolling boil, which can break down the texture and dull the flavors; keep it at a lively simmer.
Cut your bread into thin slices and brush with olive oil. Next, sprinkle with thyme and then season with sea salt.: The final act is about contrast and comfort, where hot, silky Roasted Tomato Soup meets crunchy, savory baguette . Grated cheese adds a salty umami lift that pairs beautifully with the roasted profile. When plating, taste once more for seasoning, and spoon into warmed bowls to maintain temperature. A typical error is serving on cold plates or with under-toasted bread; warm everything so the textures and temperatures sing together.
Place the bread on a baking sheet and place under the broiler for 2 minutes. Then turn the bread over, and repeat on the other side for about 1 minute – keep an eye on it as you don't want it to burn!: While the soup simmers the kitchen fills with toasting aromas, and brushing each slice with olive oil ensures an even, golden result. The oil promotes crisping and helps the thyme and salt to adhere. Slice uniformly so each piece toasts at the same rate, and resist the urge to use too much oil which will make the bread soggy instead of crisp.
Next, sprinkle with thyme and then season with sea salt: The fresh thyme releases its fragrance when warmed on the bread, creating an herbal note that matches the soup. A light sprinkle of salt brightens the flavor and balances the olive oil. Over-seasoning at this stage can overshadow the soup, so use a light hand and taste one slice before finishing the batch.
Place the bread on a baking sheet and place under the broiler for 2 minutes. Then turn the bread over, and repeat on the other side for about 1 minute – keep an eye on it as you don't want it to burn: Under the broiler the surface will bubble and take on golden brown spots quickly, filling the kitchen with toasty, nutty smells. Because broilers vary, watch closely and remove slices as they reach a deep golden color to avoid bitterness from burning. Use an aluminum baking sheet and position the rack appropriately so the bread crisps without charring too fast. A common pitfall is leaving the oven unattended during broiling, which can result in blackened edges in seconds.