Mushroom Lentil Spaghetti Squash Casserole

Mushroom Lentil Spaghetti Squash Casserole

This filling and delicious Mushroom Lentil Spaghetti Squash Casserole is low in fat and high in protein and fiber!


A filling and delicious, Mushroom Lentil Spaghetti Squash Casserole that is low on fat and high on protein and fiber!

Remember last week, when I said that I’d give you a delicious, healthy recipe? I’m sure you’re looking at the title and photos and thinking, “Creamy Mushroom Casserole? Healthy? Seriously, lady?” My answer to those is, “Yes, Yes and most definitely.”

This recipe brings the comfort of homemade casseroles to the table, while being filled with protein, fiber and little-to-no fat! I love using spaghetti squash in place of pasta, because it’s very filling, has potassium plus the other nutritional benefits of winter squashes. Soft tofu takes the place of heavy cream to keep the protein count up in a semi-sneaky way. Mushrooms, lentils and kale are simple ingredients that give the dish excellent flavor!

Basically, it’s too cold for most of the country to be eating cold things (or wanting to at least), but you still want to spring back from the decadent meals of the holidays. That’s what makes the casserole perfect for this time of year!

Oh, and I can’t forget to mention that I’m going to have some FABULOUS bloggers guest posting on Vegan Yack Attack this month! These people are all amazing and I truly can’t wait to show you what recipes they have to offer. No to mention, the recipes will all be healthy to help us start the new year off right!

A filling and delicious, Mushroom Lentil Spaghetti Squash Casserole that is low on fat and high on protein and fiber!

A filling and delicious, Mushroom Lentil Spaghetti Squash Casserole that is low on fat and high on protein and fiber!

Mushroom Lentil Spaghetti Squash Casserole

Mushroom Lentil Spaghetti Squash Casserole

Yield: 4 servings
Prep Time: 20 minutes
Cook Time: 50 minutes
Total Time: 1 hour 10 minutes

A filling and delicious, Mushroom Lentil Spaghetti Squash Casserole that is low on fat and high on protein and fiber!


  • 3 pound spaghetti squash, sliced in half lengthwise with seeds removed
  • 1/2 cup dry red lentils
  • 1 cup vegetable broth
  • 1 cup diced yellow onion
  • 3 cloves garlic, minced
  • 8 ounces button mushrooms, sliced with stems removed
  • 7 ounces soft tofu, rinsed
  • 1/2 cup unsweetened plain non-dairy milk
  • 1 1/2 tablespoons tamari
  • 1/2 teaspoon dried sage
  • 1/4 teaspoon dried thyme
  • 3 cups chopped kale, with ribs removed
  • Salt & black pepper, to taste
  • 1 tablespoon nutritional yeast
  • 1 tablespoon quick-cooking oats


  1. Preheat your oven to 375F. Place the two squash halves, cutside-down, into a large baking dish. Fill the baking dish with a 1/4" of water and poke holes in the rinds of the squash, using a fork.
  2. Once the oven is to temperature, bake for 30-40 minutes, or until the rind is soft.
  3. While the squash is baking, bring the vegetable broth to a boil in a small pot over high heat. Add the lentils in and return to a boil, then reduce heat to a simmer. Cover (make sure it doesn't overflow!) and cook for 20 minutes or until soft.
  4. In a large, non-stick saute pan, heat the onion and garlic over medium, until the onions begin to clear. You can add a tab of coconut oil to the pan for easier sauteing. Next, add the mushrooms to the pan and saute until soft, about 3-4 minutes.
  5. Blend the tofu and non-dairy milk together until very smooth. Add it to the saute pan along with the liquid aminos, sage, and thyme. Stir together and bring to a simmer. Adjust the heat to low-medium and fold in the chopped kale. Once the lentils are done cooking, stir them into the pan, as well.
  6. Turn off the stove and take the pan off of the heated burner. When the squash is cooked, take it out of the oven and adjust oven temperature to 350F.
  7. Wait 10 minutes before scraping the squash from the rind with a fork into a colander to let the excess liquid drip out. Add the squash to the saute pan and fold the mixture together. Season with salt and pepper to taste. Then place it in an 8" square casserole dish.
  8. Sprinkle the nutritional yeast and oats over the top and bake for 15-20 minutes. Serve warm!
Nutrition Information:
Yield: 4 Serving Size: 1 grams
Amount Per Serving: Unsaturated Fat: 0g

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A filling and delicious, Mushroom Lentil Spaghetti Squash Casserole that is low on fat and high on protein and fiber!

Fill your tummy with this scrumptious, warming, Mushroom Lentil Spaghetti Squash Casserole, to ward off the winter chills!

A filling and delicious, Mushroom Lentil Spaghetti Squash Casserole that is low on fat and high on protein and fiber!

If you like this casserole, you’ll love these dishes!

It’s also a part of my High-Protein Meal Prep for Two menu. Go check it out!

Image collage of 8 different dishes with text overlay reading "High-Protein Vegan Meal Prep"

27 Comments on “Mushroom Lentil Spaghetti Squash Casserole

  1. Looks pretty healthy to me–also delicious! Who doesn’t want a casserole when it’s frigid outside?

    • Right? Aside from Soup it’s the perfect winter meal! Maybe I’ll turn this into a soup… Hmm.. 😉

  2. this looks amazing! you are such a pro at combining the right ingredients to make such delicious food. and somehow it’s always photogenic!

  3. I made this for supper tonight, and it was delicious, but mine was very wet, and didn’t congeal like in the picture. Wonder what I did wrong. It was more like a stew. Delicious, but not a casserole.

  4. Wow- I really enjoyed this recipe! I’m in the middle of trying to convince my parents that vegan cooking isn’t just salads and roasted veggies, so this was a big pleaser for my omni family. One quick note though, I tasted the mix before I did the final bake and thought it was a slight bit bland. So, I upped the seasoning by adding 1/4 cup nutritional yeast and 2 tbsp chili powder to the casserole, and the parents (and me!) LOVED it!! 🙂 Oh, and I also used crimini mushrooms to give a bit of a heartier flavor instead of button mushrooms, and because, you know, that’s all I had in the fridge. ^_^

  5. Made this last night! It was so tasty! I didn’t have soft tofu (it’s not my ideal way to eat tofu) so instead I combined raw cashews and almonds in a food processor with plain almond milk. It turned out great! I also used collard greens bc that’s I didn’t have kale. This was such a great recipe and works well with substitutions! I loved the flavor of the sage with the mushrooms. Thanks for this!

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  7. Amazing! Hearty! Creamy! I chose this recipe because it seems so pretty and elegant…but I thought that I’d have to make it on a night that I’d have a LOT of time because it seems to be a lot of prep and time. Nonetheless, it’s a lot easier to make than I originally thought. I can’t wait to have this as leftovers and freeze some (the recipe made more than I planned!) for those nights where I just don’t have time to cook but want something satisfying.

  8. I made this earlier this week, and it was ok, not spectacular. I am glad I tried it, but probably won’t make it again. It took a couple hours to prep everything, but it was pretty easy. Before I baked it, I tasted it and it was pretty bland, so (as another reviewer suggested), I a tablespoon or so of chili powder and some extra sage. I also added some (rehydrated) dried black mushroom for extra texture, but in the end, the result of this recipe is kinda uniform mush. It was not liquid-y like one commenter said, it was definitely a casserole, but all of the ingredients cooked together in a way that didn’t leave much variation in texture. I thought putting oats on top of a casserole would be boring, so I used nutritional yeast and panko bread crumbs instead for more of a crunchy topping. Nevertheless, this did get eaten within a few days, and no one bad anything bad to say about it; it just wasn’t raved about. And it is definitely a power-house of ingredients, so thank you for the recipe! I always am interested in trying new things 🙂

  9. It’s in the oven as I type! Used a spaghetti squash from our own garden, as well as beet greens! Can’t wait! Looks and smells amazing.

      • Loved it!! The flavour was so lovely. I used a pinch of Icelandic lava salt, and fresh sage. The beet greens are fairly salty. Not much salt needed. Will make this again and again!

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  15. I’m a little confused by “1/2 oz of a 14 Block of Soft Tofu” … did you mean to say “1/2 of a 14 oz Block of Soft Tofu”?

    • Ah yes! My recipe plug-in transfer got a little wonky. Thank you for pointing that out. I’m just going to change it to 7 ounces.

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