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Tuna and Zucchini Noodle Casserole
with mixed greens salad

Active: 50 Total: 70

We've given the classic tuna noodle casserole a paleo-friendly twist with zucchini noodles and fresh mushrooms. We first featured a version of this meal in 2021, and this time we've included a crunchy nut topping to make it even more delicious.
Smarts: Be sure to take your time when cooking the mushrooms and onions - the longer they cook, the more flavor they will develop.



Mixed Greens Salad:
  • Vinegar, balsamic - 1 Tbsp
  • Mustard, Dijon - 1 tsp
  • Maple syrup - 1/2 tsp
  • Oil, olive - 2 Tbsp
  • Mixed greens - 5 oz
Tuna and Zucchini Noodle Casserole:
  • Onions, medium - 1/2 , diced
  • Walnuts - 1/2 cup , pulsed or crushed
  • Mushrooms, any button - 8 oz , chopped (look for pre-chopped to save time)
  • Zucchini - 12 oz , spiralized or peeled into ribbons
  • Peas, frozen or canned - 1 1/2 cups
  • Tuna, canned (5 oz / 142 g) - 2 cans , drained (look for Spanish or Italian varieties packed in olive oil )
  • Butter - 3 Tbsp + 1 Tbsp
  • Arrowroot powder - 1 tsp
  • Salt - 1/2 tsp
  • Black pepper - 1/4 tsp
  • Stock, any type - 1 1/2 cups
  • Lemon zest - 1 tsp


  1. Onions / Walnuts - Prep as directed and store separately. (Can be done up to 5 days ahead)

  2. Mushrooms (if not pre-chopped) - Prep as directed. (Can be done up to 3 days ahead)

  3. Zucchini - Turn zucchini into 'noodles' with a spiralizer, peel off strips with a peeler, or slice into cubes. (Can be done 1 day ahead)

  4. Peas - Defrost if using frozen. Drain if using canned.

  5. Tuna - Drain cans of tuna.

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  1. Heat oven to 400F / 204C.

  2. Spray a square baker with nonstick cooking spray or brush with some oil. (Note: a square baker works well for 4 servings so adjust if customizing. For any number of servings, you can use any size or shape of baking dish as long as it will comfortably hold all of the casserole.)

  3. Melt first portion of butter in a large saucepan or Dutch oven over medium heat. When butter is melted, add mushrooms and onions and cook until deep golden brown and very tender, 9 to 12 minutes.

  4. Sprinkle arrowroot powder, salt, and pepper over mushroom-onion mixture and stir until no dry spots remain.

  5. Slowly pour stock over top while whisking. Bring to a simmer. Simmer until sauce thickens slightly, 4 to 5 minutes.

  6. Remove sauce from heat and gently fold in lemon zest, zucchini noodles, peas, and tuna.

  7. Transfer into prepared baking dish.

  8. Melt second portion of butter briefly in the microwave (5-10 seconds should do it). Stir crushed walnuts into melted butter. Spread walnuts evenly over top of the casserole. 

  9. Bake until sauce is bubbling and zucchini is tender, ~ 15 minutes. Watch the nut topping carefully - it should be toasty, but cover it with foil if it starts to burn.

  10. While casserole bakes, in a large mixing bowl whisk together vinegar, mustard, maple syrup, and olive oil. Add greens on top, but wait to toss until just before serving.

  11. Season the top of the salad with some black pepper if you'd like.

  12. Serve casserole with salad on the side. Enjoy!



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