Cook the Cauliflower Mash: Place the cauliflower rice, minced garlic, and ¼ cup water in a large microwave-safe bowl. Cover the bowl with a plate and microwave on high for 12 minutes. Once done, carefully remove the plate, allowing the steam to escape, and drain any excess liquid. Use a fork to mash the cauliflower until it reaches a soft consistency. If it's still firm, continue microwaving in 1-minute intervals until it becomes tender enough to mash.
Prepare the Turkey Patties: Finely chop the parsley, setting aside a small portion for garnish. In a large mixing bowl, combine the ground turkey, panko breadcrumbs, Parmesan cheese, egg, sour cream, salt, and a few grinds of black pepper. Grate the garlic directly into the mixture and add the lemon zest. Using your hands, gently mix everything until just combined, being careful not to overwork the meat. Form the mixture into four equal patties, about ½-inch thick.
Cook the Turkey Patties: Heat the olive oil in a large nonstick skillet over medium-high heat. Once the oil is hot and shimmering, carefully place the patties in the pan. Allow them to cook undisturbed for about 4-5 minutes, until they develop a deep golden crust. Flip the patties and cook for another 4-5 minutes on the other side, ensuring they are cooked through. Transfer the patties to a plate and tent loosely with foil to keep warm.
Sauté the Spinach: Cut the zested lemon in half. In the same skillet, add the olive oil and heat over medium. Toss in the spinach, sprinkle with salt, and squeeze in the juice from one lemon half. Stir well, then cover the pan and allow the spinach to wilt for about a minute or two. Stir again to ensure even cooking, then remove from heat once softened.
Finish the Cauliflower Mash: You can leave the mash slightly chunky or blend it in a food processor for a smoother texture. Stir in the sour cream, Parmesan cheese, a small squeeze of lemon juice (about 2 teaspoons), salt, and a few grinds of black pepper. If the mash seems too thick, add a splash of water or stock to loosen the consistency. Taste and adjust seasoning as needed.
Assemble & Serve: Divide the mashed cauliflower onto four serving plates. Stir the spinach before plating it alongside the mash. Place a turkey patty on each plate and garnish with additional Parmesan and the reserved parsley. Serve immediately.