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Keto Tuna Casserole
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Keto Tuna Casserole

This creamy, cheesy, and flavorful keto tuna casserole is the perfect low-carb comfort food. Packed with protein, healthy fats, and a medley of savory flavors, it’s a family favorite that’s easy to prepare. Plus, it swaps out traditional pasta for keto-friendly zucchini noodles, ensuring you stay within your daily carb limits.
Course Main Course
Cuisine American, Keto, Low-Carb
Keyword Gluten-Free, Keto, Keto Tuna Casserole, Low-Carb
Prep Time 15 minutes
Cook Time 25 minutes
Resting Time 5 minutes
Total Time 45 minutes
Servings 6
Calories 320kcal
Cost $15-$20

Equipment

  • Medium-sized skillet
  • 9x13-inch baking dish
  • Mandoline slicer (optional, for zucchini noodles)
  • Large mixing bowl
  • Whisk
  • Cheese grater
  • Oven

Ingredients

  • 2 tbsp Butter (unsalted)
  • 1 small Onion finely diced
  • 2 cloves Garlic minced
  • 2 cups Zucchini noodles (about 2 medium zucchinis)
  • 1 cup Broccoli florets steamed
  • 2 cans (5 oz each) Tuna drained
  • 1 cup Shredded cheddar cheese (divided)
  • 1/2 cup Cream cheese softened
  • 1/3 cup Mayonnaise
  • 1/4 cup Heavy cream
  • 1 tsp Dijon mustard
  • 1 tsp Dried parsley
  • 1/2 tsp Paprika
  • Salt and pepper to taste
  • 1/3 cup Grated Parmesan cheese (optional, for topping)

Instructions

Preheat the Oven:

  • Preheat your oven to 375°F (190°C). Lightly grease a 9x13-inch baking dish with butter or cooking spray.

Prepare the Zucchini Noodles:

  • Use a mandoline slicer or spiralizer to create zucchini noodles. Lightly salt them and let them sit for 5 minutes to release excess moisture. Pat dry with paper towels.

Sauté Aromatics:

  • In a medium skillet, melt butter over medium heat. Add diced onion and minced garlic. Sauté until fragrant and translucent, about 3-4 minutes. Remove from heat.

Make the Creamy Sauce:

  • In a large mixing bowl, whisk together cream cheese, mayonnaise, heavy cream, Dijon mustard, parsley, and paprika until smooth. Season with salt and pepper to taste.

Combine the Ingredients:

  • Add the drained tuna, sautéed onion and garlic, steamed broccoli, zucchini noodles, and half of the shredded cheddar cheese into the mixing bowl with the sauce. Gently fold until evenly coated.

Assemble the Casserole:

  • Transfer the mixture into the prepared baking dish. Spread it out evenly. Top with the remaining shredded cheddar cheese and optional Parmesan cheese for an extra golden crust.

Bake the Casserole:

  • Place the dish in the oven and bake for 20-25 minutes, or until the cheese is bubbly and golden brown.

Cool and Serve:

  • Let the casserole rest for 5 minutes before serving. This helps it set and makes it easier to portion.

Notes

  • Substitutions: If you don’t have zucchini noodles, you can use spaghetti squash or thinly sliced cabbage for a similar texture.
  • Tuna Variations: Feel free to swap canned tuna with canned salmon or shredded rotisserie chicken for variety.
  • Cheese Options: Swap cheddar for mozzarella or pepper jack for a different flavor profile.
  • Make-Ahead: Prepare the casserole up to the baking step and refrigerate for up to 24 hours. Add an extra 5 minutes to the baking time when cooking from cold.
  • Storage: Store leftovers in an airtight container in the fridge for up to 3 days. Reheat in the oven or microwave until warmed through.

Pro Tip:

For even more flavor, sprinkle crushed pork rinds or almond flour on top of the casserole before baking to create a keto-friendly breadcrumb topping. This adds crunch and an irresistible texture!
Enjoy this hearty and nutritious keto tuna casserole that’s sure to satisfy cravings while keeping you on track with your low-carb goals.