Ingredients
Equipment
Method
- Preheat your oven to 375°F (190°C). Lightly grease a 9x13 inch baking dish. Bring a large pot of salted water to a boil. Add the broccoli florets and blanch for 2 minutes, just until bright green and slightly tender. Immediately drain and plunge into a bowl of ice water to stop the cooking. Drain again and set aside. This step is crucial—it ensures your broccoli stays vibrant and perfectly tender in the final bake without turning mushy.
- In a large skillet or Dutch oven over medium-high heat, melt 1 tablespoon of the butter. Add the cubed chicken, season with a pinch of salt and pepper, and cook for 5-7 minutes, stirring occasionally, until cooked through and lightly browned. Remove the chicken from the skillet and set aside on a plate. Don't worry about cooking it completely through here, as it will finish in the oven.
- In the same skillet, melt the remaining 2 tablespoons of butter over medium heat. Add the diced onion and cook for 4-5 minutes until softened and translucent. Add the minced garlic and cook for 1 more minute until fragrant. Sprinkle the flour over the onions and garlic, and cook, stirring constantly, for 2 minutes. This cooks out the raw flour taste and forms your roux, the base of your sauce.
- Slowly whisk in the chicken broth, followed by the milk and heavy cream. Continue whisking constantly to prevent any lumps from forming. Bring the mixture to a gentle simmer and cook for 3-4 minutes, whisking often, until it thickens enough to coat the back of a spoon. Remove from heat. Stir in 1.5 cups of the shredded cheddar cheese, all of the mozzarella, dried thyme, paprika, 1 teaspoon of salt, and 1/2 teaspoon of pepper. Stir until the cheese is fully melted and the sauce is smooth.
- Add the cooked chicken and blanched broccoli to the cheese sauce, gently folding to combine. Pour the entire mixture into your prepared baking dish. In a small bowl, combine the remaining 1/2 cup of cheddar cheese with the French fried onions (or crushed crackers). Sprinkle this topping evenly over the casserole.
- Bake in the preheated oven for 25-30 minutes, or until the casserole is bubbling vigorously around the edges and the topping is a deep, golden brown. Let the casserole rest for 10 minutes before serving. This rest time is non-negotiable—it allows the sauce to set slightly so you get perfect, scoopable servings instead of a soupy mess.
Notes
Chef's Tips:
• For the crispiest topping, add it during the last 10 minutes of baking if using a crumb topping like crackers or panko.
• The most common mistake is overcooking the broccoli. The 2-minute blanch is perfect—it will finish cooking in the oven.
• Serve with a simple green salad dressed with a bright vinaigrette to cut through the richness.
Food Safety:
• Ensure chicken reaches an internal temperature of 165°F before removing from the oven.
• Refrigerate leftovers within 2 hours of cooking.