Gather all your ingredients. Wash and slice the Roma tomatoes lengthwise and set them aside. Chop your onion, mince your garlic, and prepare your basil and thyme.

Preheat your oven to 375°F.

Spread the sliced tomato halves on a baking sheet. Drizzle with 2 tablespoons of olive oil and sprinkle with salt and black pepper. Bake in the preheated oven for about 1 hour.

In a large pot or Dutch oven, heat the remaining tablespoon of olive oil or butter over medium-high heat. Add the diced onion and sauté for about 5 minutes until translucent.

Add minced garlic, fresh thyme, salt, and pepper. Sauté for another minute.

Add crushed San Marzano tomatoes, chopped basil, and sugar to the pot. Reduce heat and let it simmer gently for about 10 minutes.

Carefully add the roasted tomatoes to the pot along with 2 cups of chicken stock. Bring to a low simmer and cook for an additional 30 minutes.

Using an immersion blender, carefully blend the soup until smooth. If you prefer a chunky texture, blend lightly.

Return the blended soup to the pot. Stir in the heavy cream and warm through.

Optionally, prepare mini croutons by cutting small pieces of bread into cubes, tossing with olive oil, garlic, and baking at 400°F for about 7 minutes.