Turn your Instant Pot to sauté mode. Add a drizzle of olive oil to the Instant Pot insert.
Add the garlic and onion. Saute for 2 -3 minutes until the onion softens slightly.
Add the carrots and mix. Cook for another 2 minutes, stirring frequently.
Add in the red bell pepper, diced tomatoes, celery salt and pepper to taste. Pour in the chicken stock and tomato paste. Mix until combined and add the basil leaves.
Close the lid, turning the valve to seal, and set to HIGH pressure for 15 minutes. Release the vent once it's the timer goes off by doing a manual release.
Meanwhile, prepare your baguettes by preheating your oven to 375 degrees F. Place some aluminum foil on a baking sheet. Cut your baguette into diagonal pieces, about 1 inch thick. Sprinkle easy slice with Parmesan cheese, then bake for 20 minutes, or until golden brown. Remove from the oven and serve with the tomato soup.
Remove the basil leaves and use a hand held immersion blender to purée until the soup is completely smooth. If you don't have an immersion blender, you can use a regular blender or food processor. Stir in sour cream or heavy cream, if using.
Give the soup a taste and adjust, whether you want it a bit thinner you can add more chicken broth, or adjust any salt or pepper.
Garnish with thyme, basil, and a toasted baguette topped with Parmesan cheese.