Ingredients:

  • 2 tablespoons olive oil (30 ml)
  • 1 medium yellow onion, diced (about 1 1/2 cups / 200 g)
  • 3–4 garlic cloves, minced (about 12 g)
  • 2 medium carrots, peeled and chopped (about 1 cup / 120 g) — optional
  • 1 celery stalk, chopped (about 1/2 cup / 50 g) — optional
  • 2 (28-oz / 796 g) cans crushed tomatoes OR 3 (14–15 oz / 400–425 g) cans crushed or whole tomatoes, crushed
  • 2 tablespoons tomato paste (30 g)
  • 3 cups (24 fl oz / 720 ml) low-sodium chicken broth or vegetable broth
  • 1 tablespoon granulated sugar OR 1–2 teaspoons honey (12 g / 5–10 ml), optional
  • 1 teaspoon dried basil (1 g) OR 1/4 cup fresh basil leaves, torn (6 g) added at finish
  • 1 teaspoon dried oregano (1 g)
  • 1 bay leaf
  • 1/2 teaspoon red pepper flakes (optional)
  • Kosher salt and freshly ground black pepper, to taste (start with 1 tsp salt / 6 g)
  • 1/2–3/4 cup heavy cream or half-and-half (120–180 ml) OR 1/2 cup full-fat coconut milk for dairy-free (120 ml) — optional for finishing
  • 1 tablespoon unsalted butter (14 g) — optional
  • 1–2 teaspoons lemon juice (5–10 ml) — optional
  • 1 tablespoon cornstarch mixed with 2 tablespoons cold water (8 g cornstarch + 30 ml water) — optional thickener
  • Garnishes: fresh basil leaves, croutons or grilled cheese wedges, a drizzle of olive oil, cream, or basil pesto, shaved Parmesan

Instructions:

  1. Prepare aromatics: Heat olive oil in a skillet over medium heat. Sauté diced onion until translucent and edges begin to color, about 6–8 minutes. Add garlic and sauté 30–60 seconds until fragrant. Add chopped carrots and celery and cook 2–3 minutes to slightly soften.
  2. Build the soup in the crockpot: Transfer sautéed aromatics to the crockpot. Add crushed tomatoes, tomato paste, broth, sugar or honey if using, dried basil, oregano, bay leaf, red pepper flakes, and 1 teaspoon salt. Stir to combine.
  3. Slow-cook: Cover and cook on LOW for 4–6 hours or on HIGH for 2–3 hours. Soup is done when carrots are tender, flavors are melded, and the soup is visibly simmering with a deep aroma.
  4. Remove bay leaf and blend: Remove the bay leaf. Use an immersion blender to puree the soup to desired smoothness directly in the crockpot. Or carefully transfer batches to a countertop blender (cool slightly, fill under 3/4 full) and blend until smooth; return to crockpot.
  5. Finish and adjust: Stir in heavy cream, half-and-half, or coconut milk and butter; heat on HIGH for 10–15 minutes to warm through. If a thicker texture is desired, whisk cornstarch slurry and stir into the soup; cook 5–10 minutes until slightly thickened. Taste and adjust seasoning with salt, pepper, and 1–2 teaspoons lemon juice if needed.
  6. Serve: Ladle into bowls and garnish with torn basil, a drizzle of cream or olive oil, croutons or crumbled grilled cheese, and shaved Parmesan if desired. Serve hot alongside grilled cheese or crusty bread.