Italian Tomato-Basil Soup

Ingredients

• 10 ml (2 tsp)olive oil
• 1 smallred onion, diced
• 794 g (28 oz; 1 can)no-salt-added tomato purée
• 240 ml (1 cup)low-sodium vegetable broth
• ¼ tspsalt
• ⅓ cupfresh basil leaves, thinly sliced
• 10 ml (2 tsp)balsamic vinegar

Instructions

1. 1

   Soften the onion

   Heat the olive oil in a large saucepan over medium heat. Add the diced onion and cook, stirring occasionally, until fully softened, about 8 minutes.

2. 2

   Simmer the soup

   Add the tomato purée, vegetable broth and salt, then bring to a boil over high heat. Reduce the heat to medium-low and simmer uncovered for about 5 minutes, until the flavours have come together. For a thinner soup, drizzle in more broth.

3. 3

   Finish and serve

   Stir in the basil and balsamic vinegar. Ladle into bowls and serve hot or chilled.

What is Italian tomato-basil soup?

This is a straightforward tomato soup flavoured with onion, fresh basil and a little balsamic vinegar. Tomato soups are made in many Italian and Italian-inspired kitchens, and this quick version focuses on a short list of pantry-friendly ingredients.

Tomato purée gives the soup its body, while basil and vinegar add freshness and tang. The result is versatile enough to serve on its own or alongside a sandwich or salad.

Nutrition and macros by portion

The nutrition label shows one serving as written: 110 calories, 4g protein, 21g carbs, 3g fat.

The tomato purée provides most of the carbohydrates, while olive oil contributes most of the fat; the broth and vegetables provide a little protein. The supplied nutrition per serving is 110 kcal, with 4 g protein, 21 g carbohydrates and 3 g fat. Pair a bowl with a grilled cheese sandwich or a protein-rich side to make the meal more substantial.

Choosing the tomatoes

Tomato purée: use the no-salt-added variety specified, so you can control the seasoning yourself. It also keeps the method simple, with no need to chop or cook down fresh tomatoes.

Vegetable broth: low-sodium broth lets the tomato flavour stay in the foreground. Add a little extra at the end if you prefer a thinner consistency.

Build flavour with the onion

Soft onion: give it the full 8 minutes over medium heat, stirring now and then. It should be tender rather than browned, which makes a gentle savoury base for the soup.

Steady heat: if the onion starts catching or colouring quickly, turn the heat down slightly. Letting it soften gradually helps avoid bitter browned bits.

Simmer and season

Brief simmer: after bringing the tomato mixture to a boil, lower the heat to medium-low and simmer uncovered for about 5 minutes. This gives the ingredients time to meld without reducing the soup too much.

Final seasoning: taste after the basil and vinegar are stirred in, then adjust salt if needed. Add extra broth in a small drizzle if the soup seems thicker than you like.

Keep the basil fresh

Fresh basil: slice the leaves thinly and stir them in after simmering. Adding them at the end preserves their bright, aromatic character.

Balsamic vinegar: the small amount brings a sweet-sour edge to the tomatoes. Stir it through well so the flavour is evenly distributed.

Serving ideas

With a sandwich: serve the soup hot with grilled cheese for a simple, comforting meal. A crisp green salad is another easy accompaniment.

As a sauce: spoon it over pasta for a quick tomato sauce, or chill it for a refreshing summer side. If using it for pasta, add garlic and crushed red pepper to the soup as suggested in the recipe description.

Recipe notes & tips

• Dice the onion evenly so it softens at a consistent rate.
• Stir the onion occasionally while it cooks to prevent it catching on the pan.
• Keep the saucepan uncovered during the 5-minute simmer.
• Add extra broth a little at a time to reach your preferred thickness.
• Stir in the basil and balsamic vinegar just before serving.

Variations

• Add garlic: soften a finely chopped clove with the onion for extra savoury flavour.
• Add chilli: stir in crushed red pepper for a gentle heat, especially if serving the soup with pasta.
• Make it creamy: swirl a little cream into each bowl just before serving.
• Add vegetables: simmer finely diced carrot with the onion until tender.
• Serve it chilled: cool the finished soup, refrigerate it and serve cold as a summer side.

Common mistakes to avoid

• Browning the onion: keep the heat at medium and stir occasionally so it softens without catching.
• Boiling for too long: reduce the heat after the mixture boils and simmer for about 5 minutes.
• Adding all the extra broth at once: drizzle it in gradually and stop when the texture is right.
• Cooking the basil for too long: stir it in after the simmer to retain its fresh flavour.
• Oversalting early: use the stated amount first, then taste and adjust at the end.

How to store

Cool leftovers promptly, transfer them to an airtight container and refrigerate for up to 3 days. Reheat gently in a saucepan, stirring occasionally; add a splash of broth if it has thickened. The soup can also be served chilled.

Frequently asked questions