Cheesy, creamy, and low carb, the Tex-Mex Keto Squash Casserole is a delightful twist on a classic side dish. This casserole is perfect for family gatherings, potlucks, or a cozy weeknight dinner. With its vibrant flavors and comforting texture, it stands out as a healthy option while being incredibly satisfying. Whether you’re following a keto diet or just looking to enjoy more vegetables, this casserole promises to be a winner at your table.

Jump to:
- Why You’ll Love This Recipe
- Tools and Preparation
- Essential Tools and Equipment
- Importance of Each Tool
- Ingredients
- For Garnish
- How to Make Tex-Mex Keto Squash Casserole
- Step 1: Preheat the Oven
- Step 2: Cook the Squash and Onions
- Step 3: Combine Ingredients
- Step 4: Prepare for Baking
- Step 5: Bake Your Casserole
- How to Serve Tex-Mex Keto Squash Casserole
- As a Main Dish
- With Grilled Proteins
- Topped with Avocado
- As a Breakfast Option
- With Fresh Salsa
- How to Perfect Tex-Mex Keto Squash Casserole
- Best Side Dishes for Tex-Mex Keto Squash Casserole
- Common Mistakes to Avoid
- Storage & Reheating Instructions
- Refrigerator Storage
- Freezing Tex-Mex Keto Squash Casserole
- Reheating Tex-Mex Keto Squash Casserole
- Frequently Asked Questions
- Can I make Tex-Mex Keto Squash Casserole ahead of time?
- What can I substitute for sour cream?
- Is Tex-Mex Keto Squash Casserole suitable for meal prep?
- Can I add more vegetables to this casserole?
- Final Thoughts
- 📖 Recipe Card
Why You’ll Love This Recipe
- Flavor-packed: The combination of summer squash, cheddar cheese, and ro*tel tomatoes creates a deliciously bold taste.
- Easy to prepare: With just 15 minutes of prep time, you can have this dish ready for the oven in no time.
- Versatile serving options: This casserole pairs well with grilled meats or can stand alone as a vegetarian dish.
- Low carb goodness: Perfect for keto diets, it keeps the carbs low while offering high flavor.
- Great for meal prep: Make it ahead of time and reheat for quick meals throughout the week.
Tools and Preparation
To make your Tex-Mex Keto Squash Casserole smoothly, having the right tools on hand is essential. Ensuring you have everything ready will save time and make cooking enjoyable.
Essential Tools and Equipment
- Large skillet
- Medium-sized casserole dish
- Mixing bowl
- Knife
- Cutting board
Importance of Each Tool
- Large skillet: Ideal for cooking the squash and onions evenly while allowing excess liquid to evaporate.
- Mixing bowl: A spacious bowl helps combine all ingredients thoroughly without making a mess.
Ingredients
Cheesy, creamy and low carb squash casserole makes the perfect side dish.
Ingredients:
– 1 tsp olive oil
– 2 pounds summer squash, sliced
– 1 cup diced onion
– 1 can rotel tomatoes, drained (may use mild if desired)
– 1 ½ cups cheddar cheese, grated (reserve 1/2 cup for topping)
– ½ cup sour cream
– ½ cup mayonnaise
– ¼ tsp salt
– ¼ tsp black pepper*
For Garnish
- 2 tablespoons fresh parsley, finely chopped

How to Make Tex-Mex Keto Squash Casserole
Step 1: Preheat the Oven
Preheat your oven to 350 degrees Fahrenheit. This ensures that your casserole will bake evenly.
Step 2: Cook the Squash and Onions
- Heat olive oil in a large skillet over medium heat.
- Add sliced summer squash and diced onions to the skillet.
- Cook and stir occasionally until tender, about 8–10 minutes.
- Drain any excess liquid from the squash mixture.
Step 3: Combine Ingredients
In a large mixing bowl:
1. Stir together the drained squash and onion mixture with sour cream, mayonnaise, rotel tomatoes, salt, black pepper, and most of the cheddar cheese (reserve 1/2 cup for topping).
2. Adjust seasoning according to your taste preferences.
Step 4: Prepare for Baking
Pour the mixture into a medium-sized casserole dish. Sprinkle with reserved cheddar cheese on top.
Step 5: Bake Your Casserole
Bake in the preheated oven until cheese is melted and bubbly, approximately 20–30 minutes. After baking, allow it to set for about 5–10 minutes before serving. Enjoy your flavorful Tex-Mex Keto Squash Casserole!
How to Serve Tex-Mex Keto Squash Casserole
Serving your Tex-Mex Keto Squash Casserole can elevate any meal. Here are some creative ways to enjoy this delicious dish.
As a Main Dish
- Pair it with a fresh salad for a fulfilling meal. The creaminess of the casserole complements crisp greens beautifully.
With Grilled Proteins
- Serve alongside grilled chicken or steak. The flavors of the squash casserole enhance the smokiness of grilled meats.
Topped with Avocado
- Add slices of ripe avocado on top. This adds creaminess and healthy fats, making the dish even more satisfying.
As a Breakfast Option
- Enjoy it as a breakfast side. The cheesy goodness goes well with eggs for a low-carb morning boost.
With Fresh Salsa
- Drizzle some homemade salsa on top. The acidity of the salsa brightens the flavors in the casserole.
How to Perfect Tex-Mex Keto Squash Casserole
Perfecting your Tex-Mex Keto Squash Casserole is easy with a few simple tips.
- Use Fresh Ingredients: Fresh summer squash will give you the best texture and flavor.
- Adjust Spice Levels: Feel free to add jalapeños or chili powder for extra heat if desired.
- Let It Rest: Allowing the casserole to sit for 5-10 minutes after baking helps it set and makes serving easier.
- Experiment with Cheese: Try mixing different cheeses like pepper jack or mozzarella for varied flavors.
- Add More Veggies: Incorporate bell peppers or zucchini for added nutrition and color.
- Store Properly: Keep leftovers in an airtight container in the fridge for up to 3 days.

Best Side Dishes for Tex-Mex Keto Squash Casserole
Pairing your Tex-Mex Keto Squash Casserole with the right sides can enhance your dining experience. Here are some great options:
- Cauliflower Rice: A perfect low-carb alternative to traditional rice, enhancing the Tex-Mex theme.
- Grilled Asparagus: Lightly seasoned asparagus adds a crunchy contrast to the creamy casserole.
- Zucchini Noodles: These noodles are a great way to incorporate more veggies while keeping carbs low.
- Guacamole: Creamy guacamole pairs wonderfully, adding richness that complements the dish.
- Chili Lime Corn Salad: A refreshing salad that adds sweetness and tang, balancing out savory flavors.
- Spicy Black Bean Salad: This side brings protein and spice, creating an exciting flavor combination with the casserole.
- Stuffed Bell Peppers: Filled with cheese and spices, they make an excellent companion for this hearty dish.
- Crispy Brussels Sprouts: Roasted until crispy, these sprouts provide a delightful crunch alongside your casserole.
Common Mistakes to Avoid
Making the Tex-Mex Keto Squash Casserole can be simple, but there are a few common pitfalls. Here are some mistakes to watch for:
Overcooking the Squash: If you cook the squash too long, it can become mushy. Aim for tender but firm squash after sautéing.
Skipping Ingredient Measurements: Not measuring ingredients correctly can alter the dish’s flavor and texture. Always measure your cheese and seasoning.
Using the Wrong Cheese: Cheddar is recommended for this recipe. Substituting with other cheeses may change the flavor profile significantly.
Not Draining Excess Liquid: Failing to drain the cooked squash can lead to a watery casserole. Make sure to remove any excess moisture before mixing.
Ignoring Cooking Time: Cooking for too short or too long a time can affect how bubbly and melted the cheese becomes. Keep an eye on it while baking.
Storage & Reheating Instructions
Refrigerator Storage
- Store in an airtight container.
- The casserole will last up to 4 days in the refrigerator.
Freezing Tex-Mex Keto Squash Casserole
- Use a freezer-safe container or heavy-duty freezer bags.
- The casserole can be frozen for up to 3 months.
Reheating Tex-Mex Keto Squash Casserole
- Oven: Preheat to 350°F and cover with foil. Bake for about 20 minutes or until heated through.
- Microwave: Heat in a microwave-safe dish for 2-3 minutes, stirring halfway through for even heating.
- Stovetop: Warm in a skillet over medium heat, stirring occasionally until heated through.

Frequently Asked Questions
Can I make Tex-Mex Keto Squash Casserole ahead of time?
Yes, you can prepare it ahead of time and store it in the refrigerator. Just bake it when you’re ready to serve.
What can I substitute for sour cream?
Greek yogurt is a great alternative if you’re looking for a lighter option while keeping that creamy texture.
Is Tex-Mex Keto Squash Casserole suitable for meal prep?
Absolutely! It’s perfect for meal prepping as it stores well and reheats easily, making it a convenient choice throughout the week.
Can I add more vegetables to this casserole?
Definitely! Feel free to add bell peppers, zucchini, or even spinach for added flavor and nutrition without significantly increasing carbs.
Final Thoughts
The Tex-Mex Keto Squash Casserole is not only delicious but also versatile. This dish makes an excellent side or main course that fits well into low-carb diets. You can customize it by adding your favorite veggies or adjusting spices to suit your taste. Give it a try; you won’t be disappointed!
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📖 Recipe Card
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Tex-Mex Keto Squash Casserole
- Total Time: 45 minutes
- Yield: Serves approximately 6 people 1x
Description
Tex-Mex Keto Squash Casserole is a flavorful, creamy dish that brings the best of Tex-Mex cuisine to your table without the carbs. This casserole combines fresh summer squash, sharp cheddar cheese, and zesty ro*tel tomatoes for a delightful medley of tastes and textures. Ideal for family gatherings or cozy weeknight dinners, it offers a healthy yet satisfying option for those following a keto diet or simply looking to incorporate more vegetables into their meals. With a quick preparation time and versatile serving options, this casserole is bound to become a favorite among your loved ones.
Ingredients
- 2 pounds summer squash, sliced
- 1 cup diced onion
- 1 can ro*tel tomatoes, drained
- 1 ½ cups grated cheddar cheese (reserve ½ cup for topping)
- ½ cup sour cream
- ½ cup mayonnaise
- Olive oil, salt, black pepper
Instructions
- Preheat your oven to 350°F.
- In a large skillet, heat olive oil over medium heat. Add sliced squash and diced onions. Cook until tender (8–10 minutes), then drain excess liquid.
- In a mixing bowl, combine the drained squash and onions with sour cream, mayonnaise, ro*tel tomatoes, salt, black pepper, and most of the cheddar cheese (reserve ½ cup for topping). Mix well.
- Pour the mixture into a medium casserole dish and sprinkle reserved cheddar on top.
- Bake for 20–30 minutes until cheese is melted and bubbly. Let cool for 5–10 minutes before serving.
- Prep Time: 15 minutes
- Cook Time: 30 minutes
- Category: Main
- Method: Baking
- Cuisine: Tex-Mex
Nutrition
- Serving Size: 1 cup (240g)
- Calories: 280
- Sugar: 3g
- Sodium: 450mg
- Fat: 20g
- Saturated Fat: 7g
- Unsaturated Fat: 11g
- Trans Fat: 0g
- Carbohydrates: 13g
- Fiber: 3g
- Protein: 10g
- Cholesterol: 35mg