This oven-roasted, sheet-pan tomato, leek and red pepper soup is all about simplicity and depth of flavour. The vegetables are tumbled onto a single baking tray and roasted until soft and lightly caramelised, allowing the oven to concentrate their natural sweetness and infuse them with the aroma of thyme. Once blended with vegetable stock, the result is a silky, richly savoury soup that comes together with minimal effort. Finished with torn pieces of mozzarella, it's comfort food built on the pure intensity of roasted vegetables.
Why You'll Love this Roasted Tomato, Leek and Red Pepper Soup
- Everything roasts together on one sheet pan (baking tray): maximum flavour, minimum effort, and minimal washing up.
- Roasting the vegetables draws out and intensifies their natural sweetness and savoury depth.
- A silky, comforting texture, with no complicated steps.
- Finished with torn mozzarella for gentle richness, contrast and a boost of protein.
- Ideal for late summer and early autumn, when tomatoes and peppers are at their sweetest and most abundant. Roasting is one of the best ways to transform a garden or allotment glut into something deeply flavoured, comforting, and full of natural richness.
If you enjoy this, you might also like my Carrot & Red Pepper Soup, which uses the same sheet-pan roasting method for deep, sweet flavour
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Key Ingredients & Notes
- Tomato, leeks and red peppers -Tomatoes and peppers are a natural pairing. Tomatoes bring in a sweet gentle tang, while peppers add warmth and vibrant colour. Leeks provide a mild, rounded base and are a softer alternative to onions, allowing the roasted flavours to shine.
- Garlic - Adds savoury depth and balances the natural sweetness of the roasted vegetables.
- Thyme - Infuses the tray of vegetables with a, warm herbaceous note that complements the tomatoes and peppers.
- Sea Salt and olive oil - Coating the vegetables before roasting with olive oil and sea Salt enhances their flavour and encourages caramelisation.
- Vegetable stock - Made from the green parts of the leek for a low waste approach. Also, check out my "How to make vegetable stock like a chef"
- Mozarella - Used for its gentle, milky flavour and because it adds protein without overpowering the soup. It also provides a lovely textural contrast.
- Black pepper - Used for seasoning.
See the recipe card for quantities.
How to Make Sheet Pan Roasted Tomato, Leek and Red Pepper Soup
- Prep the vegetables: Cut the peppers lengthwise and halve the tomatoes. Cut the leeks into large chunks.
- Separate the garlic cloves, leaving the skins on.
- Separate the thyme into sprigs.
- Put the peppers, tomatoes, leek, garlic and thyme onto a sheet pan (baking tray)
- Coat with olive oil and sea salt and lay over the sprigs of thyme.
- Preheat the oven to 180ºC.
- Roast the vegetables for about 30 minutes, or until they are soft and slightly browned.
- While the vegetables are roasting, make the vegetable stock by placing the green parts of the leek in 1 litre of water, then bringing it to a boil.
- Reduce to a simmer for 20 minutes.
- Strain and set aside the stock. Discard the leek leaves.
- After the vegetables are roasted, add everything, including the thyme, to a pot. With the garlic, squeeze out the soft garlic and discard the skin.
- Add the vegetable stock and blend to a smooth puree using a stick blender. If you use a food processor to blend the soup, transfer the vegetables to the blender bowl and add half the stock. Blend to a smooth puree. Transfer the blended soup back to the saucepan and add the remaining stock.
- Bring the soup to a rapid boil and immediately reduce the heat and simmer for 5 minutes.
- Add torn pieces of mozzarella and any garnish of your choice. I like to add mixed seeds and herb sauce.
Substitutions & Variations
You can use white onions instead of leeks, just a small one, cut in half, and roast with all the other vegetables. For some heat, you can add a fresh chilli to the roasting tray.
Instead of thyme, you can use oregano, or you can add just basil when blending the soup or finish with fresh basil leaves in the end.
Instead of mozzarella, ricotta, or even mascarpone. For a stronger flavour contrast, use feta.
You change the soup by omitting cheese altogether and finishing it with cream instead.
Equipment
Digital scales are a must as they ensure recipes and flavours are accurate.
A blender or a food processor is essential for pureeing the soup.
Storage
The soup without mozzarella can be stored in the fridge for up to three days. It can be frozen in an airtight container for up to three months. Defrost in the fridge overnight, then reheat gently on the stove or in the microwave.
Chefs Tips
Roasting the tomatoes, leeks and peppers first concentrates their natural sugars and umami, giving the finished soup a deeper, rounder flavour and texture. With simple soups like this, roasting is always preferable to me because of the flavour benefits.
Don't add all the vegetable stock at once; add a little at a time to puree the soup. If you add everything at once, the soup will splatter everywhere, and the puree will take longer to become smooth.
FAQs
Depending on your oven, it usually takes 30 to 35 minutes. You are aiming for the vegetables to blister and be lightly charred at the edges. Caramelisation in this way intensifies the vegetables' flavour and brings out their sweetness, making the soup more flavourful.
Yes, it's fine to make ahead of time and store it in the fridge for a day or two. This soup is ideal for batch cooking and freezing, making it a quick go-to for the work lunch.
All of the ingredients apart from the mozarella are vegan, so it is supper easy to make this vegan simply by omitting the mozarella. You can replace it with a vegan version of mozzarella. This soup is gluten-free too, so its really easy to make this a gluten-free and vegan soup.
Roasting uses dry heat at higher temperatures to intensify flavour. It evaporates moisture and the high heat causes caramalisation, bringing out natural sweetness. Boiling, on the other hand cooks the vegetables at lower temperatures and softens the vegetables making them easier to digest, but has little impact on flavour.
They look similar, but the key differnence is that a bisque is enriched and thickened, often with cream. Sometimes even with rice or a roux, giving a luxurious, velverty body. This roasted tomato, leek and red pepper soup is more vegetable forward, letting their natural flavours shine forth and is a bit rustic copmared to a bisque.
Related Recipes
Looking for other soup recipes like this? Try these:
Pairing Suggestions
These are my favourite dishes to serve with this roasted tomato, leek and red pepper soup, whether as a garnish or an accompaniment:
📖 Recipe
Roasted Tomato, Leek and Red Pepper Soup
Equipment
- Digital scales
- Blender or Food processor
Ingredients
- 1 kg Tomatoes
- 250 g Leek
- 130 g Peppers
- 25 g Garlic
- 5 g Thyme
- 3 tsp Sea salt
- 1 teaspoon Black pepper
- 1 tablespoon Olive Oil
- 1 L Vegetable stock
- 125 g Mozzarella cheese
Instructions
- Wash and pat dry all of the vegetables and herbs.
- Preheat the oven to 180ºC.
- Cut the tomatoes and peppers in half lengthwise, then place them on the baking tray.
- Cut the leek into large chunks and place it onto the baking tray (only the white and light green parts). The green parts will be used to make vegetable stock.
- Add the garlic to the baking tray, skin on.
- Separate the thyme and add it to the tray. Then add one teaspoon of salt and olive oil and coat the vegetables. Roast in the oven for about 30 minutes, or until the vegetables have a bit of browning and are tender.
- While the vegetables are roasting, add the green parts of the leek to a pot with one litre of water and bring to a rapid boil. Once it comes to a boil, simmer for 20 minutes. Strain and set aside.
- Once the vegetables are roasted, transfer them into a bowl (squeeze out the garlic from its skin and discard the skin). Add the vegetable stock and blitz into a smooth puree with a stick blender. If using a food processor, add the vegetables to the blender bowl with half the stock, then add the remaining stock after the soup has been transferred to a saucepan for the next step.
- Bring the soup to a rapid boil, then simmer for five minutes. Add the salt, a little at a time, checking the seasoning as you go, until it suits your taste. Season with black pepper.
- Serve hot, with torn bits of mozzarella and any other garnish of your choice.
Nutrition
NOTES
Food Safety
- Wash your hands regularly while preparing, handling and cooking food.
- Wipe down countertops and high-contact points regularly.
- If you cook meat and fish, do not use the same utensils on cooked food that previously touched raw meat. Use separate chopping boards for meat and fish. Wash your chopping boards immediately after use.
- Thoroughly cook food to a minimum temperature of 165 °F (74 °C).
- Don't leave food at room temperature for extended periods (more than 2 hours).
- Store food correctly.
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