In a large dutch oven, heat olive oil over medium-high heat. Once hot, add diced onion and cook for 4-5 minutes or until beginning to soften. Add in garlic and cook another minute.
Dice cauliflower into florets, then add to the onions. Stir in salt and pepper.
Pour in veggie broth and bring to boil. Once boiling, reduce heat to medium-low and simmer for 20 minutes or until cauliflower is tender.
Once cauliflower is tender, add butter, lemon juice, and nutmeg. Turn off heat and let sit 10 minutes.
Using an immersion blender or regular blender, blend soup until completely smooth.
Meanwhile, heat a saute pan over medium-high heat. Add oil. Once hot, add bread cubes and spices. Cook 7-8 minutes, tossing occasionally until bread is toasted.
Add soup to bowl and top with parsley and croutons.