Grammie Bea's Scalloped Potato and Tuna Casserole

Cozy, comforting, and brimming with nostalgic charm, Grammie Bea's Scalloped Potato and Tuna Casserole is the ultimate one-dish meal for family dinners or gatherings. Featuring layers of tender russet potatoes, flaky tuna, and creamy cheddar cheese sauce, this hearty casserole strikes the perfect balance between rich, cheesy indulgence and satisfying protein-packed flavor. A hint of garlic powder enhances the dish with subtle aromatics, while a golden, buttery breadcrumb topping adds an irresistible crunch. Easy to prepare and baked to bubbly perfection, this dish is a classic crowd-pleaser that pairs beautifully with a crisp side salad. Perfect for weeknight dinners or potluck occasions, this tuna casserole will transport you straight to the warmth of a home-cooked meal.

Nutriscore Rating: 68/100

Prep Time:30 mins

Cook Time:60 mins

Total Time:90 mins

Servings: 6

Ingredients

• 6 medium Russet potatoes
• 4 tablespoons Unsalted butter
• 3 tablespoons All-purpose flour
• 3 cups Milk
• 1 teaspoon Salt
• 0.5 teaspoon Ground black pepper
• 0.5 teaspoon Garlic powder
• 2 cups Shredded cheddar cheese
• 2 5-ounce cans Canned tuna
• 1 medium Onion
• 0.5 cup Breadcrumbs
• 0.25 teaspoon Paprika
• 2 tablespoons Fresh parsley (optional, for garnish)

Directions

Step 1

Preheat your oven to 375°F (190°C). Grease a 9x13-inch baking dish and set aside.

Step 2

Peel and slice the potatoes into thin, even rounds (about 1/8-inch thick). Place the slices in a bowl of cold water to prevent discoloration while preparing the other ingredients.

Step 3

Finely dice the onion and drain the canned tuna. Flake the tuna with a fork and set aside.

Step 4

In a medium saucepan, melt the butter over medium heat. Once melted, stir in the flour to create a thick roux. Cook the roux for 1-2 minutes, stirring constantly.

Step 5

Gradually whisk in the milk, making sure to break up any lumps. Continue to cook the mixture, stirring frequently, until it thickens (about 5 minutes).

Step 6

Season the sauce with salt, pepper, and garlic powder. Stir in 1 1/2 cups of the shredded cheddar cheese until melted and smooth. Reserve the remaining cheese for topping.

Step 7

Drain the potato slices and pat them dry with a clean kitchen towel.

Step 8

To assemble the casserole, layer one-third of the potato slices in the bottom of the prepared baking dish. Sprinkle with one-third of the diced onions and flaked tuna. Pour one-third of the cheese sauce over the layer. Repeat this process two more times, finishing with a layer of cheese sauce on top.

Step 9

Sprinkle the reserved shredded cheese evenly over the top of the casserole. In a small bowl, mix the breadcrumbs with the paprika and sprinkle this mixture over the casserole.

Step 10

Cover the baking dish tightly with aluminum foil and bake in the preheated oven for 40 minutes. Then, remove the foil and bake for an additional 20 minutes to allow the top to become golden brown and bubbly.

Step 11

Remove the casserole from the oven and let it cool for 10 minutes before serving. Garnish with fresh parsley, if desired.

Nutrition Facts

Serving size	(2344.3g)

Amount per serving	% Daily Value*
Calories	3115.1

Total Fat 140.2g	0%
Saturated Fat 86.3g	0%
Polyunsaturated Fat 0.5g
Cholesterol 452.0mg	0%
Sodium 5268.2mg	0%
Total Carbohydrate 347.4g	0%
Dietary Fiber 23.3g	0%
Total Sugars 58.7g
Protein 138.3g	0%

Vitamin D 367.4IU	0%
Calcium 2777.6mg	0%
Iron 17.0mg	0%
Potassium 7388.5mg	0%

*The % Daily Value tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.

Source of Calories

Fat: 39.4%

Protein: 17.3%

Carbs: 43.4%