Set your Instant Pot to the Sauté function. Add 2 tablespoons Olive Oil, then sauté 2 medium Onion, 4 cloves Garlic, 2 medium Carrots, and 2 stalks Celery until softened and fragrant, about 5 minutes.
Stir in 28 ounces Canned Tomatoes , 2 tablespoon Tomato Paste , 4 cups Vegetable Broth , 1 teaspoon Salt, 1/2 teaspoon Black Pepper, and half of the fresh basil leaves. Mix well to combine all flavors.
Lock the Instant Pot lid in place, set the valve to Sealing, and cook on High Pressure for 15 minutes. Once done, allow a natural release for 10 minutes, then quick release any remaining pressure.
Carefully use an immersion blender (or transfer in batches to a blender) and blend the soup until smooth and creamy.
Switch back to Sauté mode, stir in 1 cup Heavy Cream, and adjust seasoning with more salt and pepper if needed. Add remaining 1/2 cup Fresh Basil for brightness.
Ladle into bowls and serve hot with crusty bread, grilled cheese, or croutons for a cozy, comforting meal.