Introduction

This Low Carb Keto Tuna Casserole with Spinach is a creamy, comforting dish perfect for keto enthusiasts. It combines savory tuna, nutritious spinach, and a rich, cheesy sauce for a satisfying meal that’s easy to prepare. Ideal for weeknight dinners or meal prepping.

The image shows a baked dish in a white ceramic baking dish with green edges, resting on a dark textured cloth over a white marbled surface. The dish has three visible layers: the top layer is golden brown and crispy with melted cheese and breadcrumbs, the middle layer consists of creamy white sauce mixed with small chunks of light brown chicken, and the bottom layer has dark green spinach leaves mixed with the creamy sauce. The edges of the dish have some browned cheese overflow. In the blurry background, there are two yellow lemons. photo taken with an iphone --ar 4:5 --v 7

Ingredients

Two (5-ounce) cans of oil-packed tuna, drained
10 ounces frozen spinach, thawed and squeezed dry (or 8-10 cups fresh spinach, sautéed and drained)
4 ounces full-fat cream cheese, softened
1 cup heavy cream
1 cup shredded cheddar cheese, divided
1 cup shredded mozzarella cheese, divided
½ cup diced yellow onion
2 cloves garlic, minced
2 tablespoons unsalted butter
½ teaspoon salt
¼ teaspoon black pepper
½ teaspoon dried dill
½ cup pork rind crumbs (optional, for topping)

Instructions

Step 1: Preheat your oven to 375°F (190°C) to ensure even cooking of the casserole.
Step 2: Prepare the spinach. If using frozen, fully thaw and squeeze out excess water using a clean towel or cheesecloth. For fresh spinach, sauté until wilted and squeeze out moisture. Set aside.
Step 3: In a large skillet or oven-safe casserole dish, melt the butter over medium heat. Add diced onion and sauté for 5-7 minutes until translucent. Add minced garlic and cook for 1 minute until fragrant, avoiding burning.
Step 4: Reduce heat to low. Add softened cream cheese to the skillet and stir until melted and smooth. Slowly pour in heavy cream while stirring constantly until the sauce is smooth and slightly thickened.
Step 5: Stir in ¾ cup of cheddar and ¾ cup of mozzarella cheese until melted and creamy. Season with salt, black pepper, and dried dill. Taste and adjust seasonings as desired.
Step 6: Add drained tuna and squeezed spinach to the sauce. Gently mix to combine evenly.
Step 7: If your skillet is not oven-safe, transfer the mixture to a greased 9×13 inch casserole dish and spread evenly.
Step 8: Sprinkle the remaining ¼ cup of cheddar and ¼ cup of mozzarella cheese over the top. If using, evenly top with pork rind crumbs for a crispy crust.
Step 9: Bake in the preheated oven for 20-25 minutes until bubbly around edges and cheese on top is melted and golden.
Step 10: Remove from oven and let the casserole rest for 5-10 minutes before serving to allow it to set.

Tips & Variations

For a stronger tuna flavor, add a third can of tuna.
Use fresh spinach if preferred, but be sure to sauté and squeeze out excess moisture to prevent a watery casserole.
Experiment with different cheeses like Monterey Jack, Colby Jack, or smoked Gouda for extra flavor.
Use almond flour mixed with grated Parmesan cheese as an alternative topping to pork rind crumbs.
Ensure cream cheese is softened beforehand for a smooth, lump-free sauce.
Add a pinch of red pepper flakes for a subtle heat boost.

Storage

Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat gently in the microwave or oven until warmed through. Avoid overheating to maintain creaminess and prevent drying out.

How to Serve

A baked dish with three visible layers in a white rectangular baking dish with a green rim, placed on a white marbled surface. The bottom layer shows creamy cooked spinach mixed with chunks of light-colored chicken or fish, surrounded by a rich white sauce. Above this is a thick creamy white layer with melted cheese, topped by a golden-brown, crispy breadcrumb crust that is speckled with darker browned spots. The dish looks warm and cheesy with bubbling edges, showing a soft, rich texture beneath the crunchy top. Photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use water-packed tuna instead of oil-packed?

Yes, but oil-packed tuna provides richer flavor and healthy fats better suited for keto. If using water-packed, be sure to drain thoroughly and consider adding a bit more butter or cream to maintain richness.

Is fresh spinach better than frozen for this recipe?

Frozen spinach is convenient and holds up well in casseroles, but fresh spinach can be used if wilted and drained properly. Removing excess moisture is key to avoid a watery casserole either way.