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5 from 2 votes

Keto Broccoli Mushroom Casserole

This casserole is a side dish of fresh mushrooms and broccoli florets coated in a creamy cheese sauce. Low carb, keto-friendly, and perfect for the holidays!
Prep Time10 mins
Cook Time30 mins
Total Time40 mins
Course: Side Dish
Cuisine: American
Servings: 8
Calories: 339kcal


  • 1 lb broccoli
  • 1 lb mushrooms
  • 1/2 small onion finely diced
  • 2 garlic cloves finely minced
  • 4 ounces cream cheese softened
  • 1/2 cup mayo
  • 1/2 cup sour cream full fat
  • 1/4 cup heavy cream
  • 1 1/2 cups cheddar cheese freshly grated
  • 1/2 cup mozzarella cheese
  • 1/4 tsp red crushed pepper optional
  • salt and pepper to taste
  • oil for cooking mushrooms and onions


  • Boil the broccoli for 3 minutes in boiling salted water. Place the broccoli in a colander and discard any excess water. Pat dry the broccoli with a paper towel if necessary. 
  • Preheat oven to 350 degrees F. 
  • In a medium skillet, add some butter and let it melt over medium heat. Add the mushrooms and cook for 5 minutes, stirring frequently. 
  • Add the onions and cook for 1 minute. Stir in the fresh garlic and red crushed pepper and cook for 20 seconds. Season with salt and pepper. 
  • In a small bowl, combine the cheddar cheese and mozzarella cheese. 
  • In a large bowl, combine the softened cream cheese, mayo, sour cream, heavy cream, and 1/4 cup of the cheese mixture. 
  • Add the mushroom mixture and broccoli to the cream cheese mixture and mix well. 
  • Place the broccoli mixture into a 9x9 baking dish and top it off with the remaining cheese. Cover with aluminum foil and bake for 20 minutes. Uncover and bake for an additional 5-10 minutes. Enjoy! 


  • Because this is a keto meal and doesn't contain any flour or thickening agents, the sauce will thin out a bit as it bakes. Therefore make sure to remove any excess liquid from the broccoli and mushrooms!
  • You may use any type of cheese you prefer! Colby Jack cheese or pepper Jack cheese are excellent options!
  • Want to make it spicy? Add a generous amount of red crushed pepper and a pinch of cayenne pepper.


Calories: 339kcal | Carbohydrates: 8g | Protein: 12g | Fat: 30g | Saturated Fat: 13g | Polyunsaturated Fat: 7g | Monounsaturated Fat: 8g | Trans Fat: 1g | Cholesterol: 67mg | Sodium: 347mg | Potassium: 448mg | Fiber: 2g | Sugar: 4g | Vitamin A: 1030IU | Vitamin C: 53mg | Calcium: 255mg | Iron: 1mg