Southwestern Vegetarian Casserole
This is vegetarian comfort food at its best! A flavorful filling of beans, veggies, and spices is topped with fluffy cheddar drop biscuits and baked to perfection.
Even though I grew up in a part of the U.S. where Midwestern convenience meets Southern decadence, I’ve never been crazy about casseroles. One casserole I can always get behind is a tamale pie—a flavorful Southwestern filling topped with fluffy masa.
Recently, I was craving this hearty dish but was all out of masa. I spied a carton of buttermilk in my fridge and thought, why not top it with biscuits instead?
And with that, this Southwestern Vegetarian Casserole was born. This satisfying vegetarian meal has a generous filling of spiced veggies and beans with tender, crispy biscuits on top.
It’s great for a weekend family dinner or on a weeknight with a little wiggle room. This recipe makes six servings, but you could stretch it to serve eight with a side dish or two. I would recommend a citrusy cabbage salad or a nopalitos cactus salad.
How to Make Southwestern Vegetarian Casserole
This recipe has two components: the filling and the drop biscuits. Each is prepared separately and then assembled in a casserole dish.
- For the filling, a rainbow of chopped veggies, beans, and spices are cooked on the stovetop then poured into a casserole dish.
- The drop biscuit dough is made in a large bowl, portioned, and gently placed on top of the filling. There is no need to roll out and cut the biscuit dough.
- The biscuits are spruced up with shredded cheddar cheese both in the dough and on top.
- The whole thing goes in the oven and bakes for about 20 minutes, just long enough to clean up the kitchen and set the table.
Tips for Biscuit Success
While some biscuit-topped casseroles use rolled and cut biscuits, I went with drop biscuits for a few reasons. They’re quick, easy, and less messy. They also spread and puff up nicely as they bake, covering the filling and allowing you to portion and serve the casserole however you’d like.
Most important: They’re fluffy rather than flaky like most cut biscuits are. The tops get crispy and moisture in the filling keeps the biscuits tender. While flaky biscuits are fantastic, cooking them atop a moist filling isn’t the best way to encourage flaky layers.
The key to fluffy drop biscuits is to handle the dough with a light touch. The more the dough is mixed, the tougher it’ll get. After adding the buttermilk, mix just until any large dry pockets of flour have disappeared and then stop mixing it.
Portion the dough and dust it with a little flour before placing it into the casserole dish. This should be done gently and without overworking the dough.
Customizing Southwestern Vegetarian Casserole
You can swap out ingredients to your heart’s content. I’ve provided measurements for the veggies for easy swapping—just make sure to always include the onion, bell peppers, garlic, and well-drained canned tomatoes.
When making substitutions, remember to use ingredients that cook in a similar way with similar water content and cook time.
- Make it whole wheat: Swap all or half of the all-purpose flour in the biscuits for white whole wheat flour.
- Make it spicy: Leave the seeds in the jalapeño and, if you’d like, double it. You can even add diced jalapeño to the biscuit dough.
- Swap the squash: Replace it with chopped cauliflower or cooked, cubed sweet potato. Add them with the beans and 1/4 cup broth or water since squash contains more water.
- Swap the mushrooms: Try diced eggplant instead or replace with chopped fresh tomatoes for more acidity.
- Make it meaty: Swap the mushrooms and half of the beans for cooked and drained ground beef, turkey, or chicken.
- Swap the kale: Any chopped, leafy green will work, such as spinach, chard, or collard greens.
- Go all tomato: Swap the salsa for a puréed tomato salsa or tomato sauce.
How to Store and Reheat
I thought this recipe wouldn’t keep well since drop biscuits tend to be lackluster as they cool. But there’s something about baking them on top of the moist filling that gives it longevity.
To store: Tightly cover leftovers and store them in the fridge for up to three days.
To reheat: I highly suggest reheating it in the oven, so the biscuits get a second life. Microwaving makes them a bit chewy.
Remove the dish from the fridge to let it warm up a bit as the oven preheats, about 15 minutes. Cover the dish with foil and reheat it in a 400°F oven for 15 minutes until bubbly. Remove the foil and bake for an additional 10 minutes to re-crisp the biscuits.
If you’re not planning to eat all the leftovers, I recommend scooping your portion into a smaller oven-safe dish so that you don’t end up reheating it repeatedly.
If You Like Flavors of the Southwest
- Butternut Squash and Black Bean Skillet Dinner
- Southwest Skillet Chicken with Beans and Corn
- Mexican Quinoa Salad with Black Beans, Corn, and Tomatoes
- Tex-Mex Shepherd’s Pie
- Three Sisters Casserole with Cornbread Topping
Heat the oven:
Preheat the oven to 450°F and grease a 9x13-inch casserole dish with cooking spray.
Cook the vegetables:
Heat a large, deep skillet or Dutch oven over medium heat. Add the oil and onion. Sauté until the onion begins to soften, about 2 minutes.
Add the squash, mushrooms, bell pepper, and jalapeño, if using, and sauté until the squash begins to soften, 3 to 4 minutes.
Add the kale, garlic, chili powder, salt, and black pepper. Sauté until the kale is wilted, about 3 minutes.
Assemble the filling:
Make sure the canned beans and tomatoes are drained well. Otherwise, the filling will be too wet.
Add the beans, tomatoes, and salsa to the skillet. Cook, stirring frequently, until it comes up to a boil, then turn off the heat. Taste the filling and adjust the seasoning with chili powder and salt.
Carefully pour the filling into the prepared casserole dish and set it aside while you make the biscuits.
Make the biscuit dough:
In a medium bowl, mix 2 cups (280g) of flour, baking powder, sugar, salt, and baking soda with a wooden spoon or rubber spatula. Add the cubed butter and cut it into the flour using a pastry cutter or two butter knives until the mixture resembles small peas covered in flour.
Add the buttermilk and 1 cup of cheddar cheese. Gently mix until just combined with no big pockets of dry flour left. Do not overmix.
Form the biscuits:
In a shallow bowl, add the remaining 1/3 cup (46g) flour. Using a measuring cup, scoop about 1/2 cup of the biscuit dough and add it to the flour. Cover the top of the dough with flour using your fingers. Lift the dough and gently toss it back and forth between your hands to remove any excess flour.
Place the dough on top of the vegetable filling—you’ll be making 6 biscuits total, placing them in two rows of 3 biscuits.
Top the biscuits with the remaining 1/2 cup cheese.
Bake and serve:
Bake the casserole for 20 to 25 minutes, until the filling is bubbly, and the biscuits are golden brown and puffy.
If the tops of the biscuits are becoming too dark before the 20-minute mark, cover the casserole dish with a piece of foil and continue baking them to make sure they cook all the way through.
Let it cool for 5 to 10 minutes before scooping and serving.