Heat a large heavy-bottomed pot over medium heat. Add olive oil and 1 tablespoon butter (or vegan butter). When shimmering, add diced onion, carrot, and celery. Sprinkle a pinch of salt. Cook, stirring occasionally, until vegetables are softened and translucent, about 8–10 minutes; do not brown.

Add garlic and tomato paste

Add minced garlic and tomato paste to the softened vegetables. Cook, stirring, 1–2 minutes until the garlic is fragrant and the tomato paste darkens slightly — this deepens the tomato flavor.

Add tomatoes and stock

Add the crushed canned tomatoes, vegetable stock, dried thyme, bay leaf, sugar, salt, and black pepper. Stir to combine and bring to a gentle simmer. Reduce heat to maintain a low simmer, partially cover, and cook for 20–25 minutes to allow flavors to meld and vegetables to soften completely.

Blend until smooth

Remove the bay leaf. Use an immersion blender to purée the soup directly in the pot until smooth. Alternatively, transfer the soup in batches to a blender (cool slightly, fill blender no more than half full) and blend until silky, then return to the pot. Be careful of hot splashes.

Creamy Finish (Vegan option noted)

Adjust seasoning and add cream

With the soup over low heat, stir in the heavy cream (or canned coconut milk/cashew cream for vegan) and remaining 1/2 tablespoon butter or vegan butter. Heat gently — do not boil once cream is added — for 3–4 minutes until warmed through. Taste and adjust salt, pepper, and sugar as needed. If the soup is too thick, thin with up to 1/2 cup additional stock or water to reach desired consistency.

Finish with basil

Stir in most of the chiffonaded fresh basil, reserving a small amount for garnish.

To Serve

Toast brioche

Heat a skillet over medium heat and brush both sides of brioche slices with olive oil or a little butter. Toast until golden brown on both sides, about 1–2 minutes per side. If using parmesan, sprinkle on while still warm so it melts slightly.

Ladle and garnish

Ladle the soup into warmed bowls. Drizzle a little extra cream or a few drops of olive oil if desired. Top with reserved basil and a light sprinkle of flaky sea salt. Serve with toasted brioche on the side.