Prep the oven: Preheat to 375°F (190°C). Grease a 9x13-inch baking dish.
Par-cook the broccoli: Steam or microwave until crisp-tender, about 3–4 minutes.
Drain well so the bake doesn’t get watery.
Make the sauce: In a skillet over medium heat, melt butter. Add garlic and cook 30 seconds. Stir in cream cheese until smooth.
Thin and season: Whisk in heavy cream and chicken broth.
Add onion powder, smoked paprika, mustard powder, salt, and pepper. Simmer 2–3 minutes until slightly thickened.
Add cheese: Remove from heat and stir in 1 cup shredded cheddar until melted and creamy.
Combine: In the baking dish, mix turkey and broccoli. Pour the cheese sauce over and toss to coat evenly.
Top and bake: Sprinkle remaining 1/2 cup cheddar and Parmesan on top.
Bake 18–22 minutes, until bubbly and golden around the edges.
Finish: Rest 5 minutes, garnish with parsley or chives, and serve warm.