Preheat the oven to 350 F.
Cut cauliflower into florets. Put in a large bowl.
In a small bowl, mix 1 tsp turmeric and 1/2 tsp onion powder with 1.5 tbsp avocado oil. Pour over cauliflower and toss.
Spread cauliflower on baking sheet. Roast cauliflower for about 30 minutes.
To make the dressing: put olive oil, mayo, Dijon, capers, garlic, lemon, turmeric, black pepper in a small food processor. Process until smooth.
To make the salad: in a salad bowl or individual bowls, put the lettuce on the bottom. Top with roasted cauliflower. Pour dressing over top. Use tongues to mix dressing in. Garnish with hemp seeds.