Preheat and prep: Heat your oven to 375°F (190°C). Pat the shrimp dry and season with salt, pepper, and half the paprika or Cajun seasoning.

Sauté aromatics: In a large skillet over medium heat, add olive oil and 1 tablespoon butter. Cook onion for 2–3 minutes until translucent. Add garlic and cook 30 seconds until fragrant.

Cook the veggies: Add zucchini and a pinch of salt. Sauté 3–4 minutes until slightly tender. Stir in cauliflower rice and cook another 3–4 minutes to steam off excess moisture.

Wilt the greens: Add spinach and cook until just wilted. Transfer the mixture to a greased 9x13-inch baking dish and spread in an even layer.

Make the cream sauce: In the same skillet, melt the remaining 2 tablespoons butter. Reduce heat to low. Whisk in heavy cream and cream cheese until smooth and slightly thick, 2–3 minutes. Stir in lemon zest, lemon juice, garlic powder, onion powder, and remaining paprika/Cajun seasoning. Season to taste.

Combine with shrimp: Add the seasoned shrimp to the cream sauce and toss to coat. They do not need to be fully cooked at this stage.

Assemble the casserole: Pour the shrimp and sauce over the veggie layer. Gently spread to distribute the shrimp evenly.

Add the cheesy topping: Mix cheddar and mozzarella. Sprinkle evenly over the top. Add Parmesan for extra browning if using.

Bake: Bake for 12–15 minutes, until the cheese is melted and bubbling and the shrimp are pink and opaque.

Broil for a golden top: If you want extra color, broil for 1–2 minutes. Watch closely to avoid burning.

Rest and serve: Let the casserole rest for 5 minutes so the sauce sets slightly. Garnish with parsley and cracked pepper. Serve warm.