Ingredients

For the Casserole:

4 boneless, skinless chicken breasts (about 1.5 pounds/680 grams)
Provides lean protein and serves as the main component of the casserole. Ensure the chicken breasts are of even thickness for uniform cooking.
4 cups broccoli florets (about 1 pound/450 grams)
Adds a crunchy texture and nutrients. Use fresh broccoli for the best results; if using frozen, thaw and drain thoroughly.
1 tablespoon olive oil
Used for sautéing the chicken and adding healthy fats.
1/2 teaspoon garlic powder
Enhances the flavor of the chicken. Use high-quality garlic powder for the best taste.
1/2 teaspoon onion powder
Adds a subtle depth of flavor.
Salt and black pepper to taste
Essential for seasoning the chicken and overall flavor balance.
1 cup shredded cheddar cheese (120 grams)
Provides a rich, cheesy flavor. Use sharp or mild cheddar according to preference.
1 cup shredded mozzarella cheese (120 grams)
Adds a gooey texture and complements the cheddar.
1/2 cup sour cream (120 milliliters)
Adds creaminess and a tangy flavor to the sauce. Opt for full-fat sour cream to maintain the keto-friendly profile.
1/2 cup mayonnaise (120 milliliters)
Contributes to the creamy texture of the casserole. Choose a low-carb or keto-friendly brand.
1/2 cup chicken broth (120 milliliters)
Adds moisture and helps blend the sauce ingredients. Use low-sodium broth to control salt levels.
1 teaspoon dried thyme
Adds a subtle herbal note. You can substitute with dried rosemary or oregano if desired.
1 teaspoon dried basil
Enhances the overall flavor profile of the casserole.
1/4 teaspoon crushed red pepper flakes (optional)
Adds a hint of heat. Adjust based on your spice preference.
2 tablespoons chopped fresh parsley (for garnish)
Provides a fresh, vibrant touch to the finished casserole.

Instructions

Preheat the Oven: Begin by preheating your oven to 375°F (190°C). Grease a 9×13-inch baking dish or a similarly sized casserole dish to prevent sticking.
Prepare the Chicken: Pat the chicken breasts dry with paper towels to remove excess moisture. Season both sides with salt, black pepper, 1/2 teaspoon garlic powder, and 1/2 teaspoon onion powder.
Sear the Chicken: Heat 1 tablespoon olive oil in a large skillet over medium-high heat. Add the seasoned chicken breasts and cook for 5-7 minutes on each side, or until they are golden brown and reach an internal temperature of 165°F (74°C). The chicken should be cooked through but not overly browned.
Rest and Dice: Remove the chicken from the skillet and let it rest on a cutting board for 5 minutes. Once rested, dice the chicken into bite-sized pieces.
Cook the Broccoli: While the chicken is resting, steam or blanch 4 cups of broccoli florets until they are crisp-tender. If steaming, do so for about 3-4 minutes until the broccoli is bright green and slightly tender. If blanching, cook for 2-3 minutes in boiling water, then immediately transfer to an ice bath to stop the cooking process. Drain well.
Prepare the Sauce: In a medium mixing bowl, combine 1 cup shredded cheddar cheese, 1 cup shredded mozzarella cheese, 1/2 cup sour cream, 1/2 cup mayonnaise, 1/2 cup chicken broth, 1 teaspoon dried thyme, 1 teaspoon dried basil, and 1/4 teaspoon crushed red pepper flakes (if using). Mix well until the ingredients are thoroughly combined.
Combine Chicken and Broccoli: In a large mixing bowl, combine the diced chicken and steamed broccoli. Gently stir in the prepared sauce, ensuring that the chicken and broccoli are evenly coated.
Transfer to Baking Dish: Pour the chicken and broccoli mixture into the prepared baking dish, spreading it evenly with a spatula.
Bake the Casserole: Place the baking dish in the preheated oven and bake for 25-30 minutes, or until the casserole is bubbly and the cheese is melted and lightly golden on top.
Broil for a Golden Top (Optional): For a more golden top, turn the oven to broil during the last 2-3 minutes of baking. Keep a close eye on the casserole to prevent burning.
Cool and Garnish: Once baked, remove the casserole from the oven and let it cool for 5-10 minutes. Garnish with 2 tablespoons chopped fresh parsley before serving.
Serving Suggestions: Serve the Keto Chicken and Broccoli Casserole as a main dish. It pairs well with a simple side salad or a serving of cauliflower rice for a complete meal.
Storing Leftovers: Store any leftover casserole in an airtight container in the refrigerator for up to 4 days. Reheat in the oven or microwave until warmed through.
Freezing: This casserole can be frozen for up to 2 months. Allow it to cool completely before transferring to a freezer-safe container or individual portions. Thaw overnight in the refrigerator before reheating.
Reheating: To reheat, bake the thawed casserole at 350°F (175°C) for 20-25 minutes, or until heated through. If reheating individual portions, microwave on high in 1-2 minute intervals, stirring between each interval.
Meal Prep: This casserole is ideal for meal prepping. Prepare a batch in advance and portion it out for convenient, low-carb meals throughout the week.
Customization Options: Feel free to customize the casserole by adding other low-carb vegetables, such as bell peppers or mushrooms. You can also experiment with different cheese varieties or herbs to suit your taste preferences.
Dietary Considerations: This recipe is keto-friendly, low-carb, and suitable for those following a gluten-free diet. Ensure all ingredients used are certified gluten-free if you have specific dietary restrictions.