Add 1 tablespoon avocado oil to large pot and heat pot on stovetop over medium-high heat. Swirl or tilt pot occasionally to distribute oil across entire surface and heat until oil is hot and shimmery.
When oil is ready, add 1 medium onion and 2-3 cloves garlic. Stir to incorporate then sauté 3 minutes or until onions and garlic have softened.
Add 2 cups chopped bell pepper, 2 cups chopped zucchini, and 2 cups chopped eggplant. Stir to incorporate, then cook 5 minutes, stirring occasionally.
After 5 minutes, add 1 28-ounce can tomatoes, 1 28-ounce carton vegetable stock, 1 teaspoon salt, 2 teaspoons dried basil, and 1 teaspoon dried parsley. Stir gently to incorporate ingredients then bring mixture to boil.
Once boiling, immediately reduce heat under pot to medium-low. Simmer uncovered 20 minutes or until vegetables have softened.
Once vegetables have softened, ladle approximately 50% of soup into traditional blender. Set blender aside and let soup cool 3 to 5 minutes, then carefully blend mixture until completely smooth. See Notes for tips on how to safely blend hot liquids.
Return blended mixture to pot and stir to reincorporate. Taste soup and season with additional salt and/or freshly cracked black pepper if desired.
Ladle prepared soup into serving bowls. Top each serving with pesto to taste, ½ tablespoon chiffonaded basil leaves, and shaved fresh parmesan if desired. Serve immediately with pieces of baguettes.
Recipe Notes
Immersion Blender: If using an immersion blender, first ladle 50% of the soup into a large bowl and set it aside. Remove the soup pot from the heat and let the soup cool slightly, then insert the immersion blender and blend the soup until completely smooth. Return the reserved soup to the pot and stir to reincorporate.
To Chiffonade the Basil: Stack the fresh basil leaves on top of each other, then roll the whole stack lengthwise into a cylinder. Slice perpendicular to the basil roll, creating long, thin ribbons of basil.
Tips for Blending Hot Liquids
Fill blender no more than halfway. Work in batches as needed.
Let soup cool slightly before blending.
Remove center cap from blender lid and cover opening in lid with dish towel. Hold blender lid down while blending.
Blend in short bursts until desired consistency is achieved.