Heat olive oil in a large soup pot over medium heat.
Add chopped onion and sauté until soft and translucent.
Stir in minced garlic and cook until fragrant.
Add cauliflower florets and diced potatoes to the pot.
Sprinkle in cumin, oregano, salt, and black pepper.
Pour in vegetable broth and stir well.
Bring the soup to a boil, then reduce heat and simmer for 20 minutes.
Blend the soup until smooth and creamy using an immersion blender.
Stir in fresh lemon juice and remove from heat.
Garnish with fresh parsley and serve warm.