Step 1

Preheat oven to 400°F.

Step 2

Add the tomatoes, onion, and garlic to a large baking sheet.

Step 3

Drizzle with the olive oil. Add 1 teaspoon of salt, the Italian seasoning, and the pepper. Stir well so that the vegetables are well coated in the oil and seasoning.

Step 4

Roast in the oven for 20 minutes. Use a spatula to stir and flip over the vegetables. Return to the oven for another 20 minutes.

Step 5

Carefully transfer the roasted vegetables to a large soup pot. Add the broth and basil.

Step 6

Use an immersion blender to blend the soup until smooth.

Step 7

Add the parmesan cheese, and sugar. Stir to combine. Taste to see if you need to add the remaining 1/2 teaspoon of salt.

Step 8

Place the pot over medium heat. Simmer for five minutes.

Step 9

You can serve it as is, if you don't mind seeds. Or, press it through a fine mesh strainer to make it completely smooth.

Step 10

Optional: Serve drizzled with a spoonful of heavy cream and a grilled cheese sandwich for dipping.