Vegetarian Tater Tot Casserole (with Pumpkin, Mushrooms & Spinach)

This vegetarian tater tot casserole swaps the usual ground beef and canned soup for earthy mushrooms, garlicky spinach, and a creamy, savory pumpkin base, all under a golden layer of crispy tots. It's cozy fall comfort food that comes together in one skillet, and it's easy to make completely vegan, too.

Casserole, hot dish, or whatever else you want to call it, is a meal that's undeniably delicious, comforting, and able to satisfy even the hungriest of appetites. But unfortunately for my skinny jeans, it's not necessarily the healthiest dish out there. So I've given this upper Midwest staple a makeover.

I can only remember eating tater tot casseroles a handful of times in my life, so I had to do a little bit of research when it came time to develop this recipe. The basic formula, usually assembled and cooked in a single dish, is a meat, a canned soup, canned or frozen vegetables, and a starch. In my version, hearty brown mushrooms and fresh spinach, onion, garlic, and thyme take the place of the meat and canned vegetables, and a combination of pumpkin purée and vegetable stock binds everything together into a deliciously savory pumpkin recipe.

The tater tot topping seemed kind of untouchable in my eyes. And hello, tater tots are DELICIOUS, so why would I want to mess with that?! They provide the perfect crispy, crunchy final layer, so much so that I had a hard time not picking them all off and eating them. I bet after just one bite, you'll be hooked!

Key Ingredients & Substitutions

• Brown mushrooms. Cremini (baby bella) mushrooms give the filling a meaty, savory depth that stands in for the ground beef in a classic hot dish. White button mushrooms work too, or use a mix of shiitake and oyster mushrooms for extra flavor.
• Pumpkin purée. This is the secret to the creamy base, so there's no need for canned cream-of-anything soup. Use plain canned pumpkin (not pumpkin pie filling, which is sweetened and spiced) or homemade pumpkin purée. Butternut squash purée or mashed sweet potato make good swaps.
• Fresh spinach. Three packed cups wilt down to almost nothing. Baby kale or chopped Swiss chard can stand in; if you use frozen spinach, thaw it and squeeze out as much water as you can first.
• Vegetable stock. Loosens the pumpkin so the base stays saucy under the tots. Store-bought is fine, or make your own vegetable broth from kitchen scraps.
• Onion, garlic, and fresh thyme. The aromatic backbone of the filling. If you only have dried thyme, use 1 teaspoon instead of a tablespoon of fresh.
• Frozen tater tots. Add them straight from the freezer, no thawing needed. Most plain store-bought tots are vegan and many are gluten-free, but check the label if either matters to you.

Helpful Tips

Use one oven-safe skillet. To keep the dish count low, I sauté the vegetables and build the base on the stovetop in a 10-inch cast iron skillet, then add the tots and move the whole thing into the oven. No oven-safe skillet? Cook the base in any skillet, then transfer it to a greased 8-inch square casserole dish, arrange the tots on top, and bake until golden and bubbly.

Let the mushrooms brown. Give them a few minutes over medium heat without crowding the pan so their moisture cooks off and they pick up some color. Browned mushrooms taste far richer than steamed ones, and they won't water down the pumpkin base.

Season the base before the tots go on. Once the tater tots are in place, you can't stir in more salt. Taste the pumpkin mixture after adding the stock and adjust the salt and pepper then. Pumpkin is mild, so it usually needs a little more than you'd expect.

Pack the tots in a single, snug layer. Line them up in tight rows so they cover the whole surface. A single layer lets hot air reach every tot, so they bake up crisp instead of steaming. If you have a few left over, tuck them into any gaps along the edges.

Let it rest before serving. Five minutes out of the oven gives the bubbling base time to thicken slightly, so each scoop holds together instead of running across the plate.

Variations

• Cheesy. Stir a handful of shredded sharp cheddar or Gruyère into the pumpkin base, or scatter it over the tots for the last 5 minutes of baking. Use a dairy-free shred to keep it vegan.
• Extra protein. Add a drained can of white beans or chickpeas, or a cup of cooked lentils, to the filling along with the pumpkin.
• More veggies. Frozen peas, corn, or green beans are classic hot dish additions. Stir in about a cup with the spinach.
• Sage and smoke. Swap the thyme for chopped fresh sage and add ½ teaspoon smoked paprika for a deeper, cozier flavor.
• Veggie tot topping. Use cauliflower or sweet potato tots instead of regular potato ones, or try one of these homemade veggie tot recipes.

Serving Ideas

This casserole is a full meal on its own, but something fresh and crunchy on the side balances all that cozy richness. A simple green salad with a sharp vinaigrette is perfect, or go seasonal with roasted Brussels sprouts and apples.

For dipping those crispy tots, set out a bowl of homemade balsamic ketchup, hot sauce, or a dollop of sour cream (or vegan sour cream). It's also a great make-ahead main for a fall potluck or a meatless Thanksgiving side, since it travels well right in the skillet.

Make-Ahead & Freezing

To make it ahead, prepare the pumpkin, mushroom, and spinach base, let it cool, then cover and refrigerate it for up to 2 days. When you're ready to eat, top it with frozen tots and bake as directed, adding 5 to 10 minutes since the base starts cold. Leftovers keep in an airtight container in the fridge for 3 to 4 days. Reheat them in a 375°F oven or an air fryer rather than the microwave so the tots crisp back up.

To freeze, let the baked casserole cool completely, then wrap the skillet or dish tightly (or portion it into freezer-safe containers) and freeze for up to 3 months. Thaw overnight in the fridge, then reheat covered with foil at 375°F for about 20 minutes, uncovering for the last 10 so the topping gets crispy again. You can also freeze the unbaked base on its own and add fresh frozen tots on baking day for the crispiest results.

More Vegetarian Casseroles

If you love this vegetarian tater tot casserole, be sure to check out these other tasty recipes:

• 17 of the Best Vegetarian Casseroles
• Vegetarian Shipwreck Casserole
• Creamy Wild Rice and Mushroom Casserole
• Pumpkin Sage Baked Ziti
• Vegan Sweet Potato Shepherd's Pie

📖 Recipe