Tuna-Spinach Bake

Prep: 10 min Cook: 20 min Serves: 4 Cuisine: American

A creamy, savory tuna and spinach bake with buttery sauce, crunchy croutons, and zesty lemon—comforting, protein‑rich, and perfect for a quick weeknight dinner.

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Ingredients

  • 2 packages (10 oz. each) frozen chopped spinach
  • 1/4 cup butter or margarine
  • 1/4 cup flour
  • 1 tsp. salt
  • 1/4 tsp. pepper
  • 1/4 tsp. dry mustard
  • 1/8 tsp. onion salt
  • 2 cups milk
  • 1/2 cup mayonnaise
  • 1 Tbsp. lemon juice
  • 1 can (6.5 oz.) tuna, drained
  • 1 cup croutons

Instructions

  1. Heat oven to 350°F.
  2. Cook frozen spinach according to package directions.
  3. Melt butter in a saucepan over low heat.
  4. Stir in flour, salt, pepper, dry mustard, and onion salt until smooth.
  5. Cook over low heat, stirring until mixture is bubbly and thickened.
  6. Remove from heat and stir in milk, heating to a gentle boil while stirring.
  7. Boil and stir for 1 minute.
  8. Blend in mayonnaise and lemon juice.
  9. Fold in drained tuna and croutons.
  10. Transfer mixture to a baking dish and bake until hot and bubbly, about 15 minutes.

Tips & Substitutions

For a lighter version, consider using Greek yogurt instead of mayonnaise. You can also add grated cheese, such as cheddar or mozzarella, for extra creaminess. If you're short on time, fresh spinach can be used instead of frozen, but be sure to cook it down to remove excess moisture. This dish can be made in advance and refrigerated before baking.

Serving Suggestions

Serve this Tuna-Spinach Bake alongside a fresh green salad or steamed vegetables for a balanced meal. It pairs beautifully with Garlic Broiled Lobster Tails or can be enjoyed with crusty bread. Consider adding a squeeze of lemon over the top for a bright finish.

Storage & Reheating

Store any leftovers in an airtight container in the refrigerator for up to 3 days. To reheat, place in the oven at 350°F until warmed through, about 15-20 minutes. Alternatively, you can microwave individual portions, but baking provides a better texture.

Nutrition & Diet Analysis (per serving)

Each serving of Tuna-Spinach Bake contains roughly 1794 calories, with 1g protein, 12g carbohydrates, and 195g fat. It is a good source of vitamin C (16% of the Daily Value). Note that it is relatively high in sodium, at 2380mg per serving (103% of the Daily Value).

1794 kcal 90% DV
Protein Fat Carbs

Macronutrients

Protein 1.3g 3% DV
Total Fat 195.1g 100% DV
Carbs 12.4g 5% DV
Fiber 0.6g 2% DV
Sugar 7.6g 15% DV

Electrolytes

Sodium 2380.4mg 100% DV
Potassium 96.2mg 2% DV
Cholesterol 301mg 100% DV

Vitamins & Minerals

Vitamin A 30.8mcg 3% DV
Vitamin C 14.7mg 16% DV
Vitamin D 0.3mcg 1% DV
Calcium 73.5mg 6% DV
Iron 1.3mg 7% DV
Diet fit Low-carb
Contains Milk Egg Wheat/Gluten Fish

Estimated from ingredients & per-serving nutrition — verify against package labels for allergies or strict diets.

* % Daily Values based on a 2,000 calorie diet (FDA 2020).

Frequently Asked Questions

Can I use fresh spinach instead of frozen?

Yes, fresh spinach can be used as a substitute for frozen. You'll need about 8 cups of fresh spinach, cooked down to remove excess moisture. Sauté it in a little butter until wilted before adding it to the recipe.

Is there a gluten-free option for this recipe?

Absolutely! You can substitute the flour with a gluten-free blend or cornstarch to thicken the sauce. Ensure that the croutons are also gluten-free or replace them with crushed gluten-free crackers for added texture.

Can I make this dish ahead of time?

Yes, you can prepare the mixture a day in advance. Simply cover it and store it in the refrigerator. When ready to bake, transfer it to a baking dish and cook as directed. This can save time on busy days.

Nutrition is estimated from USDA FoodData Central ingredient data and may vary with brand, portion and preparation — see our methodology. This information is for general educational purposes only and is not medical or dietary advice (disclaimer).

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