Roast the vegetables

• Halve the tomatoes and onion and place them in a baking dish with the garlic heads.
• Drizzle with olive oil and season with salt, pepper, thyme and basil.
• Roast until the tomatoes are soft and the garlic is tender.

Blend the roasted vegetables

• Squeeze the roasted garlic out of its skins into a blender.
• Add the roasted tomatoes, onion and chicken broth.
• Blend until completely smooth.

Start the soup base

• Melt the butter in a pot.
• Stir in the tomato paste, salt, pepper, chili flakes, nutmeg and sugar.

Simmer the soup

• Pour in the blended tomato mixture.
• Simmer for a few minutes, stirring occasionally.

Finish the soup

• Turn off the heat, then stir in the heavy cream so it doesn't curdle.
• Finish with the grated Parmesan.

Make the garlic butter

• Mash the roasted garlic head with the softened butter until smooth.

Assemble the grilled cheese

• Spread the garlic butter over the outside of both bread slices.
• Layer the mozzarella and cheddar between the slices.

Toast the sandwich

• Cook the sandwich in a pan over low heat, low and slow, until golden brown and crispy on both sides.

Serve

• Cut the grilled cheese and dunk it into the warm tomato soup.