Prepare Ingredients: Preheat oven to 375°F (190°C). Cut the chicken into bite-sized pieces and chop the broccoli.
Cook Chicken: In a large skillet over medium heat, melt butter and add the chicken pieces. Season with salt and pepper. Cook until chicken is golden and cooked through.
Add Garlic: Add minced garlic to the skillet with the chicken and cook for another minute until fragrant.
Cook Broccoli: In a separate saucepan, blanch the chopped broccoli until bright green and just tender, about 3-4 minutes. Drain well.
Make Alfredo Sauce: In the same skillet with the chicken, lower the heat to medium-low and add the heavy cream, Parmesan, and nutmeg if using. Stir to combine and simmer until the sauce thickens.
Combine and Bake: Add the drained broccoli to the chicken and sauce mixture. Transfer everything to a greased baking dish and bake in the preheated oven for 15-20 minutes until bubbly and golden on top.
Serve: Remove from oven and let cool slightly before serving. Enjoy your keto-friendly chicken and broccoli Alfredo.