Begin by chopping a medium yellow onion into small, even pieces. This helps it soften quickly and meld into the soup smoothly.
Peel and grate a large carrot, aiming for fine shreds that will melt into the soup and add a natural sweetness and vibrant color.
Open the can of San Marzano tomatoes and crush them lightly with your hands or a fork to create chunky, broken-down pieces.
Heat olive oil in a skillet over medium heat. Add the chopped onion and grated carrot, sautéing for about 5-7 minutes until fragrant and slightly caramelized, with a golden hue and sweet aroma filling the air.
Transfer the sautéed vegetables to the slow cooker. Pour in the crushed tomatoes, vegetable broth, add minced garlic, smoked paprika, and season with salt and pepper.
Stir everything together to combine, then cover and set the slow cooker to low. Let it cook for 4-6 hours, during which the flavors meld and the vegetables soften into a rich, fragrant broth.
Once cooking is complete, use an immersion blender directly in the slow cooker to blend the soup until smooth and velvety. Alternatively, transfer to a blender in batches, blending until creamy.
Add the heavy cream for extra richness, stirring well. Taste and adjust seasoning with salt and pepper as needed, then let the soup rest for a few minutes to settle the flavors.
Serve the soup hot in bowls, garnished with fresh herbs or a drizzle of olive oil if desired. The finished dish should be smooth, bright, and smoky with a velvety texture and inviting aroma.
