Creating your Creamy Tomato Bisque with Grilled Cheese Croutons is straightforward if you follow these steps:

1. Sauté Vegetables: In a large pot, heat olive oil over medium heat. Add the diced onion, chopped carrot, and celery. Sauté until the onions are translucent, about 5 minutes.

2. Add Garlic: Stir in the minced garlic and cook for an additional minute until fragrant.

3. Incorporate Tomatoes: Add the chopped tomatoes (or canned tomatoes) to the pot along with the vegetable broth, dried basil, dried oregano, and sugar if using.

4. Simmer: Bring the mixture to a boil, then reduce the heat and simmer for about 20 minutes. Stir occasionally.

5. Blend: Once the soup has simmered, use an immersion blender to puree the soup until smooth. Alternatively, transfer it in batches to a standard blender.

6. Stir in Cream: Return the blended soup to the pot and stir in the heavy cream. Heat gently until warmed through. Season with salt and pepper to taste.

7. Prepare Grilled Cheese Croutons: While the soup is simmering, prepare your grilled cheese. Heat a skillet over medium heat. Spread butter on one side of each slice of bread.

8. Add Cheese: Place one slice of bread in the skillet, buttered side down. Top with mozzarella cheese, then place the second slice on top, buttered side facing out.

9. Grill: Cook until golden brown on one side, about 3-4 minutes. Flip and cook until the other side is golden and the cheese is melted.

10. Cut into Croutons: Remove from heat and let cool slightly. Cut the grilled cheese sandwich into bite-sized croutons.

11. Serve the Soup: Ladle the creamy tomato bisque into bowls and top with grilled cheese croutons.