Creamy Shells with Tuna and Spinach

Prep Time:
30 mins
Total Time:
50 mins

This update to the old-fashioned tuna casserole is just as delicious as you remember: It gets a fresh taste from spinach and a fun shape from shells.


  • 3 tablespoons extra-virgin olive oil

  • 1 small yellow onion, diced small

  • ¼ cup all-purpose flour (spooned and leveled)

  • 4 cups whole milk

  • Coarse salt and ground pepper

  • 1 hamburger bun, torn into large pieces

  • ¼ cup grated Parmesan

  • ½ teaspoon Italian seasoning

  • ½ teaspoon red-pepper flakes

  • 1 package (10 ounces) frozen chopped spinach, thawed and excess liquid squeezed out

  • 2 cans (6 ounces each) light tuna in water, drained and flaked

  • 6 ounces jumbo pasta shells (about 20), cooked according to package instructions


  1. Preheat oven to 375 degrees. In a medium pot, heat oil over medium-high. Add onion and cook until softened, about 6 minutes. Add flour and cook, stirring constantly, 1 minute. Gradually add milk, whisking constantly, and cook until slightly thickened and bubbling, about 3 minutes. Season with salt and pepper and let sauce cool slightly.

  2. In a food processor, combine bun, Parmesan, Italian seasoning, and red-pepper flakes. Process until fine crumbs form. Transfer half the mixture to a large bowl and combine with spinach, tuna, and half the sauce; season with salt and pepper. Fill each shell with 2 heaping tablespoons spinach mixture and place in a 9-by-13-inch baking dish. Top with remaining sauce and breadcrumb mixture. Bake until sauce is bubbling and breadcrumbs are golden, about 20 minutes.


Cook's Notes

Toss Together a Salad

In a large bowl, whisk together 1 tablespoon each red-wine vinegar and extra-virgin olive oil, 1/2 teaspoon sugar, and 1/4 teaspoon Italian seasoning. Season with coarse salt and ground pepper. Add 3/4 head iceberg lettuce, chopped, and 1 tomato, cut into wedges. Toss to combine.

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