01 - Preheat the oven to 425°F. Line a baking sheet with parchment paper.
02 - Toss the cauliflower florets with 1 tablespoon olive oil, salt, and pepper. Spread evenly on the prepared baking sheet.
03 - Roast for 25–30 minutes, turning once halfway through, until golden brown and tender.
04 - Place eggs in a saucepan and cover with cold water. Bring to a boil, then reduce heat and simmer for 8 minutes. Transfer eggs to ice water bath, cool completely, and peel. Slice into halves or quarters.
05 - Combine avocado, Greek yogurt, olive oil, lemon juice, garlic, parsley, salt, and pepper in a blender or food processor. Blend until smooth and creamy. Add 1 tablespoon water if needed to reach desired consistency.
06 - Arrange spinach or mixed greens, roasted cauliflower, cherry tomatoes, and sliced red onion on a large platter or in individual bowls. Top with egg halves or quarters.
07 - Drizzle generously with avocado dressing and sprinkle with toasted sunflower seeds if desired. Serve immediately while cauliflower is still warm.