High-Protein Tuna Casserole
This High-Protein Tuna Casserole is an easy 30-minute meal prep dinner made with canned tuna, zucchini, celery, red onion, Dijon mustard, mayonnaise, and melty mozzarella. It’s creamy, cheesy, filling, and made without noodles.
Servings: 4 servings
Calories: 304kcal
Ingredients
- 2 (5 oz) cans tuna in water drained, about 10 oz total
- 1 cup zucchini finely chopped
- 1 cup celery finely chopped
- 1 medium red onion finely chopped
- ⅓ cup mayonnaise
- 1 tbsp Dijon mustard
- 1 cup mozzarella cheese shredded
- 1/2 tsp sea salt
- ¼ tsp black pepper
- ¼ cup fresh parsley chopped
Instructions
- Preheat the oven to 400°F / 200°C. Lightly grease a 1-quart casserole dish.
- Drain the tuna well. If it still looks watery, press it lightly with a fork or paper towel to remove extra moisture.
- In a large bowl, mix the drained tuna, zucchini, celery, red onion, mayonnaise, Dijon mustard, 1/4 cup mozzarella cheese, garlic powder, salt, and black pepper.
- Transfer the mixture to the prepared casserole dish and spread it into an even layer. Sprinkle the remaining mozzarella cheese over the top.
- Bake for 15 minutes, or until the casserole is hot and the cheese is melted and lightly golden.
- Let it rest for 5 minutes before serving. Sprinkle with fresh parsley and enjoy.
Notes
- Drain the tuna well so the casserole doesn’t become watery.
- Finely chop the zucchini and celery so they soften slightly while baking.
- If the top browns too quickly, loosely cover the dish with foil near the end of baking.
- For meal prep, let the casserole cool completely before portioning into containers.
Nutrition
Serving: 1serving | Calories: 304kcal | Carbohydrates: 4g | Protein: 23g | Fat: 21g | Saturated Fat: 6g | Polyunsaturated Fat: 9g | Monounsaturated Fat: 5g | Trans Fat: 0.04g | Cholesterol: 61mg | Sodium: 837mg | Potassium: 364mg | Fiber: 1g | Sugar: 2g | Vitamin A: 745IU | Vitamin C: 12mg | Calcium: 184mg | Iron: 2mg | Net Carbs: 3g