Finely chop the onion, carrots, and garlic.

Heat 1 tbsp olive oil in the large saucepan over medium heat.

Sauté the chopped onion and carrots for 6 minutes, stirring until softened.

Add the garlic and cook for 1 minute, stirring until fragrant.

Add the canned chopped tomatoes and vegetable broth to the saucepan.

Stir in 1 tbsp balsamic vinegar and 1 tsp granulated sugar.

Bring the soup to a boil, then reduce the heat to a gentle simmer.

Simmer the soup for 20 minutes until the carrots are very tender.

Blend the soup in batches until completely smooth.

Return the blended soup to the saucepan and season with 1/4 tsp black pepper.

Divide the grated cheese between 4 slices of sourdough bread.

Top each cheese-covered slice with a remaining slice of sourdough bread.

Toast the sandwiches in the sandwich press for 4 to 5 minutes until golden and the cheese melts.

Ladle the hot soup into 4 bowls and place one cheesy toastie beside each serving.

Sprinkle 1 tbsp Parmesan cheese over each bowl of soup before serving.