Roast the Vegetables
Preheat oven to 400°F (convection 375°F). Toss cauliflower, zucchini, onion, and garlic with olive oil, salt, and pepper.
Spread on a baking sheet and roast for 25–30 minutes, flipping halfway, until golden and tender.
Blend
Transfer roasted vegetables to a high-speed blender or pot with an immersion blender. Add broth, water, parmesan, thyme, onion powder, and nutmeg. Blend until smooth.
Simmer & Thicken
Pour blended soup into a pot over medium heat. Stir in konjac powder (whisk well to avoid clumps).
Simmer gently for 5–10 minutes until thickened and silky. Add optional cream or protein at this stage.
Adjust & Serve
Taste and adjust salt, pepper, or herbs. Serve hot with a drizzle of olive oil, parmesan, or fresh herbs on top.