To roast the cauliflower: Preheat the oven to 450°F. Line a baking sheet with parchment paper.
Cut the cauliflower head into 2-inch pieces and add into a large mixing bowl with the olive oil, thyme, sea salt, and white pepper.
Transfer to the prepare baking sheet and spread out evenly.
Roast for 15 to 20 minutes, or until the cauliflower is golden brown.
To make the turkey: Add the ground turkey, sea salt, black pepper, garlic powder, and onion powder into a large skillet.
Cook over medium/high heat using a spatula, break it up and continue to cook until the turkey is lightly brown and fully cooked, about 10 minutes.
To make the dressing: In a small bowl, add the olive oil, apple cider vinegar, water, lemon juice, salt, and pepper. Stir to combine completely. (Dressing will naturally separate, so be sure to stir or shake before using if storing leftovers).
To assemble the salads: Chop the romaine lettuce and spinach and add to bowls.
Add the turkey, roasted cauliflower, pickled onions, peppers, and dressing.