Sauté Aromatics: Heat olive oil in a large pot over medium heat. Add chopped onion, garlic, and celery. Sauté until onions are fragrant & translucent, about 5 minutes.
1 medium onion, 4 cloves garlic, 2 sticks celery
Add Vegetables: Stir in zucchini, broccoli and vegetable broth. Bring to a boil.
1 medium zucchini, 1 medium broccoli, 4 to 4.5 cups vegetable broth
Simmer: Reduce the heat and let simmer for 10-15 minutes until the vegetables are tender. Add more water/broth if needed.
Season & Blend: Add seasoning & lemon juice and stir. Then transfer to a food processor or blender (or use an immersion blender). Reserve some broccoli for serving (optional), then blend until smooth.
1.5 teaspoon Italian seasoning, 1 teaspoon garlic powder, salt and pepper, ½ tablespoon lemon juice
Check: Test to check if you are happy with the consistency. Add more broth to thin it out or transfer it back to the pan and let simmer for longer for a thicker soup.
Serve: Serve warm with toppings of your choice such as bread croutons, toasted pumpkin seeds, zucchini noodles, fresh herbs, or swirls of cream.