Heat the olive oil in a large pot or Dutch oven over medium heat. Add the chopped onion and cook until softened, about 5-7 minutes. Add the minced garlic and cook for another minute until fragrant.

Pour in the crushed tomatoes, tomato sauce, vegetable broth, dried basil, dried oregano, and red pepper flakes (if using). Stir to combine.

Bring the soup to a simmer, then reduce the heat to low, cover, and cook for at least 20 minutes, or up to an hour, to allow the flavors to meld. The longer it simmers, the richer the flavor will be.

If you prefer a smoother soup, use an immersion blender to blend the soup until smooth. Alternatively, carefully transfer the soup to a regular blender in batches and blend until smooth. Be cautious when blending hot liquids.

Stir in the heavy cream (or coconut cream) and season with salt and pepper to taste. Heat through gently, but do not boil.

Spread softened butter on one side of each slice of bread. Place two slices of bread, butter-side down, in a skillet over medium heat. Top each slice with two slices of cheese, then top with the remaining slices of bread, butter-side up.

Cook the sandwiches until golden brown and the cheese is melted and gooey, about 3-4 minutes per side.

Remove the grilled cheese sandwiches from the skillet and let them cool slightly. Cut each sandwich into small cubes to create croutons.

Ladle the creamy tomato soup into bowls.

Top with the grilled cheese croutons.

Garnish with fresh basil or a dollop of sour cream (optional).

Serve immediately and enjoy!