In a large saucepan, heat 2 tablespoons of olive oil over medium heat. Add 2 finely chopped onions and 1 teaspoon of minced garlic, along with 2 teaspoons of dried Italian herbs. Sauté for about 5–7 minutes until the onions are soft and translucent.

Incorporate 3 stalks of finely chopped celery, 2 medium leeks, 2 peeled and finely chopped carrots, 2 medium red bell peppers, and 1 medium zucchini. Cover the pot and simmer on low heat for 20 minutes, stirring occasionally until the vegetables are tender and aromatic.

Stir in 2 cans of crushed tomatoes and 1 tablespoon of tomato paste, along with 2 cups of chicken or vegetable stock. Bring to a boil over medium-high heat, then reduce to low and simmer uncovered for an additional 20 minutes.

Once cooled, use an immersion blender to puree the mixture until smooth. For a chunkier texture, pulse briefly instead.

Taste and adjust seasoning with salt and pepper as needed. For baby-friendly portions, omit any salt.

Allow the sauce to cool completely before transferring it into airtight containers or freezer bags. Label and date the containers for your convenience.