01 -
Pour olive oil into a big soup pot and heat it on medium-high. Toss in onions, celery, and carrots when the oil's ready. Stir them around and let cook for a bit until they soften up.
02 -
Drop in the diced tomatoes (with their juice), tomato paste, chicken stock, oregano, and dried basil. Let it bubble gently, and simmer everything together until the veggies are soft.
03 -
Use either an immersion blender or a regular one to smooth out the soup to the texture you like. If you used a regular blender, put it back in the pot after blending.
04 -
Melt the butter in another pot on medium-low. Whisk in the flour, and don't stop stirring for about 10 minutes, until it turns a warm golden brown.
05 -
Take a big spoonful of the tomato soup and mix it into the roux. Stir until it forms a thick paste. Gradually add in more soup while mixing, then pour it all back into the main pot.
06 -
Stir in the Parmesan cheese, cream, salt, pepper, and fresh basil. Taste the soup, and sprinkle in more oregano or basil if you want. Warm it up gently before serving.
07 -
Keep the soup in the fridge, covered, for up to one week.