I first heard of Three Sisters Casserole almost twenty years ago, back in the dining hall in my college dorm in Boulder, Colorado. This hearty casserole always made an appearance in the fall: a mélange of seemingly canned veggies with a cornbread topping.
It wasn’t always the most popular thing on the buffet table, but as a vegetarian it became my go-to, and I knew if it were made with better ingredients it could really be a home run.
This year, as I started to think about fall menu planning, the flavors from that Three Sisters Casserole kept coming to mind. I thought, “There has to be a way to make this vegetarian main dish stand out and truly shine . . . ” Translation: no canned veggies!
What Are the "Three Sisters"?
If you’ve never heard of the “three sisters,” they were the three predominant crops planted by Native Americans: corn, beans, and squash.
They were called the three sisters because they were planted close to one another—each plant had traits that helped the others grow. The corn proved to be great structure for the beans, the beans provided nitrogen to the soil, and the squash helped prevent weeds by spreading itself along the ground.
Three Sisters Casserole From Scratch
My version takes the Southwest classic further by amping up the spice profile, tossing in a few greens for extra color and nutrition, and adding a rustic cornbread biscuit topping. Fresh veggies makes for a more interesting, toothsome texture!
Also, there’s no shame in buying pre-diced and peeled winter squash if you’re so inclined. It’s usually a little more expensive but saves you time.
How to Make-Ahead or Freeze
Feel free to make the filling in advance. It keeps, covered, in the refrigerator for up to 3 days. When you’re ready to bake off the casserole, the topping takes no time to whisk together. You can get the whole thing in the oven and dinner is ready in 30 minutes.
The casserole itself will also keep for 3 to 4 days in the refrigerator, and freezes beautifully, too. To reheat, I let it thaw in the refrigerator overnight and simply warm in a 300°F oven until heated through (or microwave if you’d like).
More Vegetarian Squash Recipes:
Three Sisters Casserole with Cornbread Topping
- For the cornbread topping:
- 1 1/4 cups yellow cornmeal
- 1/2 cup all-purpose flour (or your favorite all-purpose gluten-free flour blend)
- 2 teaspoons baking powder
- 1 teaspoon kosher salt
- 2 tablespoons unsalted butter, melted
- 1/2 cup whole milk
- 1/2 cup water
- For the filling:
- 3 tablespoons extra virgin olive oil
- 1 yellow onion, diced (about 1 cup)
- 4 cloves garlic, minced
- 1 pound butternut or kabocha squash, peeled and cut into 1-inch cubes (about 2 cups)
- 1 (15-ounce) can diced fire-roasted tomatoes
- 2 tablespoons tomato paste
- 1 teaspoon ground coriander
- 1 1/2 teaspoons ground cumin
- 1/2 teaspoon chili powder
- 1/4 teaspoon smoked paprika
- 1/2 teaspoon kosher salt
- 3/4 cup vegetable broth
- 1 cup fresh or frozen corn kernels
- 1 (15-ounce) can kidney beans, rinsed and drained
- 2 cups chopped greens (such as spinach or kale)
Preheat the oven to 350°F:
Spray a 9x13-inch baking dish with non-stick cooking spray and set aside.
Make the filling:
In a large, high-sided skillet or Dutch oven, warm the olive oil over medium heat until it’s shimmering and add the onions. Cook until translucent, about 4 to 5 minutes. Add the garlic and cook for an additional minute.
Add the squash, tomatoes, tomato paste, spices, and salt. Stir in the broth and bring mixture to a boil.
Simmer the filling:
Cover the pot and reduce heat to low. Simmer for 15 to 18 minutes, or until squash is tender.
Make the cornbread topping while the filling simmers:
In a medium mixing bowl, whisk together cornmeal, flour, baking powder, and salt. Using a wooden spoon, slowly stir in the butter, milk, and water; mix only until just combined. Set aside and let it sit for ten minutes or so, while the filling simmers.
Add the rest of the ingredients to the filling:
Stir in the corn, beans, and greens into the filling, and continue cooking, covered, for 3 to 5 minutes, until mixture has thickened slightly and all the ingredients are incorporated.
Transfer to baking dish and bake:
Scrape the filling into the prepared pan and top with generous biscuit-sized clumps of cornbread topping (this can be rustic and uneven).
Bake for 20 to 25 minutes, or until filling is bubbling and topping is golden brown.
Remove from the oven allow to cool for 5-10 minutes before serving.