One Pot Keto Tuna Casserole

Name: One Pot Keto Tuna Casserole
Prep time: 10 min
Cook time: 25 min
Total time: 35 min
Cuisine: Keto
Ingredients: 2 (5 oz) cans of tuna in water (drained); 3 oz chopped bell pepper; 1 small chopped onion; 3 tbsp avocado oil mayonnaise; 3 oz shredded mozzarella; 3 oz cottage cheese (or ricotta); 1/4 tsp red pepper flakes (optional); 1/4 tsp garlic salt; Fresh parsley for garnish

Published: July 14, 2025

by Simon

Why You’ll Love This Recipe

Quick Preparation: It takes just 30 minutes from start to finish, making it ideal for weeknight dinners.
Flavorful and Satisfying: The combination of cheese and spices creates a rich, satisfying flavor profile.
Low-Carb Delight: Perfect for those following a keto diet, with only 2.3 grams of carbs per serving.
Versatile Ingredients: Use whatever vegetables you have on hand to customize the casserole to your taste.
Easy Cleanup: Cook everything in one pot for minimal mess and hassle.

Tools and Preparation

Before jumping into the cooking process, gather your essential tools and equipment. Having everything ready will streamline the preparation of your One Pot Keto Tuna Casserole.

Essential Tools and Equipment

Baking pan (5×9-inch)
Mixing bowl
Cooking spray
Oven

Importance of Each Tool

Baking pan: A sturdy baking pan ensures even cooking and helps achieve that perfect golden crust.
Mixing bowl: Essential for combining all ingredients thoroughly, ensuring every bite is packed with flavor.

Ingredients

This keto tuna casserole is the ultimate low-carb dinner option packed with creamy sauce, cheese, and tuna. Plus, it’s insanely easy to make and will take you just half an hour.

For the Casserole

2 5-oz cans of tuna in water (drained)
3 oz bell pepper (chopped)
1 small onion (chopped)
3 tbsp avocado oil mayonnaise
3 oz mozzarella (shredded)
3 oz cottage cheese (or ricotta)
1/4 tsp red pepper flakes (optional)
1/4 tsp garlic salt

For Garnish

2 tablespoons fresh parsley, finely chopped

How to Make One Pot Keto Tuna Casserole

Step 1: Preheat the Oven

Preheat your oven to 350°F (175°C). This ensures that your casserole cooks evenly once it’s placed inside.

Step 2: Prepare Your Baking Pan

Spray a 5×9-inch baking pan with some cooking oil. This prevents sticking and makes cleanup easier.

Step 3: Mix the Ingredients

In a mixing bowl, combine all of the following:
1. Drained tuna
2. Chopped bell pepper
3. Chopped onion
4. Avocado oil mayonnaise
5. Shredded mozzarella
6. Cottage cheese (or ricotta)
7. Red pepper flakes (if using)
8. Garlic salt

Mix until well combined.

Step 4: Bake the Casserole

Pour the mixture into your prepared baking pan and spread it out evenly. Bake in the preheated oven for about 20-25 minutes or until the cheese has melted and the top turns golden brown.

Enjoy your delicious One Pot Keto Tuna Casserole!

How to Serve One Pot Keto Tuna Casserole

One Pot Keto Tuna Casserole is not just a delicious meal; it’s also versatile. You can enhance your dining experience with various serving suggestions that complement this creamy and cheesy dish.

Pair with a Fresh Salad

Green Salad: A simple green salad with mixed greens, cucumber, and a light vinaigrette adds freshness.
Caesar Salad: Add some crunch with romaine lettuce, Parmesan cheese, and Caesar dressing for a classic touch.

Add Some Crunch

Pork Rinds: Serve some pork rinds on the side for a satisfying crunch that keeps your meal low-carb.
Cheese Crisps: These are easy to make and add an extra layer of flavor. Just bake shredded cheese until crispy.

Incorporate Vegetables

Roasted Broccoli: Roasting broccoli with olive oil and garlic provides a nutrient-packed side that pairs well with the casserole.
Steamed Asparagus: Lightly steamed asparagus offers a tender yet crisp texture that complements the creamy casserole.

How to Perfect One Pot Keto Tuna Casserole

To make your One Pot Keto Tuna Casserole even better, consider these helpful tips. They will elevate the flavors and ensure perfect results every time.

Bold seasoning: Don’t be afraid to season generously. Adjust spices like garlic salt or add herbs to boost flavor.
Quality tuna: Use high-quality canned tuna for better texture and taste. Look for tuna packed in water for lower calories.
Creamy consistency: For an extra creamy dish, increase the amount of mayonnaise or cottage cheese slightly.
Cheese blend: Experiment with different cheeses like cheddar or gouda for varied flavors and textures.
Baking time: Keep an eye on baking time. Remove the casserole once the top is golden brown for best results.

Best Side Dishes for One Pot Keto Tuna Casserole

When serving your One Pot Keto Tuna Casserole, adding side dishes can enhance the meal’s overall appeal. Here are some great options to consider:

Garlic Butter Zucchini Noodles: Light and flavorful, these noodles are an excellent low-carb alternative to pasta.
Coleslaw: A crunchy coleslaw made with cabbage and a keto-friendly dressing adds texture and tanginess.
Sautéed Spinach: Quick-sautéed spinach with garlic complements the creamy casserole while adding nutrients.
Stuffed Bell Peppers: For a hearty addition, stuff bell peppers with ground meat and spices for a filling side.
Riced Cauliflower: This versatile side can be seasoned in various ways to match your casserole’s flavor profile.
Cucumber Slices: Simple cucumber slices topped with salt or vinegar provide refreshing contrast against the rich casserole.
Creamed Spinach: A rich creamed spinach is another creamy option that pairs well without increasing carb counts significantly.
Pickled Vegetables: Add tangy pickles or pickled radishes for an exciting burst of flavor alongside your casserole.

Common Mistakes to Avoid

When making One Pot Keto Tuna Casserole, there are common pitfalls that can affect the final dish. Here are some mistakes to watch out for:

Using unseasoned tuna: Always choose tuna that is well-drained and preferably packed in water. This prevents excess liquid from making your casserole soggy.
Neglecting cheese variety: Different cheeses melt differently. Using only mozzarella might lead to a lack of flavor. Consider mixing cheeses like cheddar or parmesan for a richer taste.
Overbaking the casserole: Baking for too long can dry out the casserole. Keep an eye on it and remove it once the cheese is golden brown and bubbly.
Ignoring ingredient measurements: Precision matters in cooking, especially for keto recipes. Use measuring cups to ensure the right amounts of mayonnaise and cheese for optimal creaminess.
Skipping the preheating step: Preheating your oven ensures even cooking. Don’t skip this step; it’s essential for getting the best texture in your casserole.

Storage & Reheating Instructions

Refrigerator Storage

Store leftovers in an airtight container.
The casserole will last up to 3 days in the refrigerator.

Freezing One Pot Keto Tuna Casserole

Use a freezer-safe container for freezing.
The casserole can be frozen for up to 2 months.

Reheating One Pot Keto Tuna Casserole

Oven: Preheat to 350 F and bake covered with foil for about 15-20 minutes.
Microwave: Heat in short intervals, about 1-2 minutes at a time, stirring in between until hot.
Stovetop: Place in a skillet over low heat, stirring occasionally until warmed through.

Frequently Asked Questions

What is One Pot Keto Tuna Casserole?

One Pot Keto Tuna Casserole is a low-carb meal made with tuna, cheese, and creamy sauce, perfect for keto dieters seeking quick dinner options.

Can I customize my One Pot Keto Tuna Casserole?

Absolutely! You can add vegetables like spinach or zucchini or switch up the cheese based on your preference.

How do I make my One Pot Keto Tuna Casserole creamier?

For a creamier texture, increase the amount of mayonnaise or cottage cheese used in the recipe.

Is this casserole suitable for meal prep?

Yes! One Pot Keto Tuna Casserole stores well, making it an excellent choice for meal prep throughout the week.

Final Thoughts

One Pot Keto Tuna Casserole is not only delicious but also incredibly versatile. With its creamy texture and rich flavors, this dish makes for a satisfying meal any night of the week. Feel free to customize it with your favorite ingredients or sides to suit your taste! Try this recipe today and enjoy a hearty, low-carb dinner that everyone will love.