1. Start by heating a large pot over medium heat. Add 4 teaspoons of minced garlic and sauté until fragrant, which should take about one minute. Make sure to stir frequently to prevent burning and to allow the flavors to bloom.
2. Next, add in 2 cans of diced tomatoes (drained but reserve the liquid) along with ½ teaspoon dried thyme and 1 teaspoon onion powder. Stir these ingredients together and cook for about ten minutes, allowing the tomatoes to soften and the flavors to meld.
3. Once the tomatoes have cooked down, reduce the heat to medium-low and pour in 2 cups of chicken broth and the reserved tomato liquid. Stir well, and let the mixture simmer uncovered for 35 to 40 minutes. Stir occasionally to prevent sticking and to ensure even cooking.
4. After the soup has simmered, season with garlic salt and pepper to taste. Then, carefully transfer the soup to a blender. Blend in small batches until the mixture is smooth and creamy. Pour the soup back into a large serving bowl, ensuring all the soup is blended.
5. Mix in ⅓ cup of heavy whipping cream into the blended soup, stirring until well combined. Taste the soup once more, adjusting the seasoning as necessary.
6. For the grilled cheese, heat a skillet over medium heat. Take two slices of bread and butter one side of each slice. Place one slice butter-side down in the skillet.
7. Layer 1 slice of cheddar cheese and 1 slice of provolone cheese on the bread in the skillet, then top with the other slice of bread, butter-side up. Cook until golden brown, about two minutes per side. Flip carefully to ensure even cooking and melted cheese.
8. Remove the grilled cheese from the skillet and cut it in half. Serve it alongside the warm, creamy tomato soup. Top the soup with croutons and a sprinkle of optional Parmesan cheese for garnish.
9. Enjoy this nostalgic dish, allowing the flavors to transport you back to cozy times spent with family and friends.