Step 1: Prepare the Tomato Soup : Heat olive oil and butter in a large saucepan over medium heat. Add the onion and sauté for 5–6 minutes until soft and translucent. Stir in garlic and cook for 30 seconds until fragrant. Pour in crushed tomatoes, broth, sugar, salt, pepper, and basil. Bring to a gentle boil, then reduce heat and simmer for 15–20 minutes. Blend the soup using an immersion blender (or carefully in a regular blender) until smooth. Stir in cream or milk (if using) for a silky texture. Adjust seasoning and keep warm on low heat.

Step 2: Make the Grilled Cheese Sandwiches : Heat a non-stick skillet or griddle over medium heat. Butter one side of each slice of bread generously. Place one slice, butter-side down, on the skillet. Add two slices of cheese on top. Cover with another bread slice, butter-side up. Grill for 2–3 minutes per side, pressing lightly with a spatula, until golden brown and the cheese is melted. Remove and let cool for 1 minute before slicing diagonally.

Step 3: Combine and Serve : Ladle the hot tomato soup into bowls. garnish with a swirl of cream, a sprinkle of basil, or a few croutons if desired. Serve the grilled cheese sandwiches on the side — perfect for dipping!