Crockpot Broccoli Rice Casserole (Easy Vegetarian Side)

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This crockpot broccoli rice casserole is the ultimate easy comfort food recipe for busy weeknights, holiday dinners, potlucks, and family gatherings. Made with frozen broccoli, shredded cheese, instant rice, and simple pantry friendly ingredients, this vegetarian slow cooker casserole comes together with minimal prep and no oven required.

This dish has all the classic flavors of a traditional broccoli rice casserole but is made easier in the slow cooker. It is creamy, cheesy, satisfying, and a great meatless side dish that pairs perfectly with your favorite holiday mains. (If you’re planning a full holiday menu or a Sunday dinner, don’t miss our ultimate round-up of classic Southern Vegetarian Side Dishes for even more inspiration!).

Why You’ll Love This Crockpot Broccoli Rice Casserole

• Easy hands off slow cooker recipe
• Perfect for holidays, potlucks, and Sunday dinners
• Vegetarian comfort food everyone will love
• Uses simple ingredients you may already have

What Is Broccoli Rice Casserole?

Broccoli rice casserole is a classic Southern inspired comfort food made with rice, broccoli, a creamy sauce, and plenty of cheese.

My mother in law made the best broccoli casserole. It might have been the dish she was best known for. My husband always looked forward to her broccoli casserole at Thanksgiving.

The crockpot makes this recipe especially convenient because the flavors slowly blend together while the rice absorbs the creamy sauce.

Ingredients

• 24 oz chopped frozen broccoli
• 2 cups instant white rice
• 2 cups vegetable broth
• 2 cups shredded cheddar cheese (reserve half a cup for the topping)
• 2 cans cream of celery soup (check the ingredient list to make sure it is vegetarian friendly)
• ½ teaspoon garlic powder
• ½ teaspoon onion powder

Optional Topping

• ½ cup shredded cheddar cheese
• ½ cup crushed buttery crackers, like Ritz Crackers

How To Make Crockpot Broccoli Rice Casserole

Step 1: Prepare the Slow Cooker

Spray the inside of your crockpot with non-stick cooking spray to prevent the cheese and rice from sticking to the sides.

Step 2: Add the Ingredients

Add the instant white rice, vegetable broth, and frozen chopped broccoli to the slow cooker.

In a separate bowl, whisk together the cream of celery soup, garlic powder, onion powder, and 1½ cups shredded cheese.

Pour the creamy mixture over the rice and broccoli. Stir gently until everything is well combined.

Step 3: Slow Cook

Cover the crockpot with the lid and cook on LOW for 3 to 4 hours or on HIGH for 2 to 2½ hours. Because cooking times can vary slightly by appliance, check the casserole toward the end of the cooking window to ensure the rice is completely tender. Stir once or twice during cooking.

Step 4: Add the Topping

Give the casserole a gentle stir. Sprinkle the additional half-cup of shredded cheddar cheese evenly over the top. Cover with the lid for 3 to 5 minutes to let the cheese melt completely. If you are using crushed buttery crackers for a crunchy finish, sprinkle them over the melted cheese right before moving to the next step.

Step 5: The Essential Rest Period

Turn your slow cooker to the “Warm” setting and remove the lid entirely. Let the casserole sit uncovered for 10 to 15 minutes before serving. This crucial rest period allows the cheese sauce to cool slightly and thicken up while giving the instant rice a final chance to pull in any remaining savory moisture.

Tips For The Best Crockpot Broccoli Rice Casserole

Use Fresh or Frozen Broccoli

Both work well. Fresh broccoli will have a slightly firmer texture, while frozen broccoli makes this recipe even easier. Frozen broccoli works well and does not need to be thawed first.

Stick to Instant Rice

This recipe is specifically formulated for instant white rice (minute rice). Do not substitute regular, uncooked long grain white or brown rice here. Standard raw rice requires far more liquid and a much longer cooking time to tenderize which will leave you with crunchy rice and completely mushy broccoli.

Shred Your Own Cheese (If You Can!)

While store bought shredded cheddar is a great timesaver, buying a block of sharp cheddar and shredding it yourself in the food processor makes a huge difference. Pre-packaged cheese is coated in cellulose (an anti-caking agent) that prevents it from clumping in the bag, but it also keeps it from melting into that creamy velvety sauce you want for a Southern casserole.

Don’t Skip the Rest Period

When the cooking time is up, give the casserole a good stir, turn the slow cooker to “Warm,” and leave the lid off for about 10 to 15 minutes. This allows the cheese sauce to thicken up substantially and lets the instant rice finish absorbing all those rich savory flavors from the broth and cream soup.

What To Serve With Broccoli Rice Casserole

Since it’s a rich, cheesy side dish, try pairing it with lighter or protein rich mains. This slow cooker casserole goes well with a crisp green garden salad, roasted garlic green beans, vegetarian protein options like BBQ tofu or grilled seitan, or alongside other hearty Thanksgiving vegetarian dishes.

How To Store Leftovers

Store leftover broccoli rice casserole in an airtight container in the refrigerator for up to 4 days.

Reheat individual portions in the microwave or warm gently on the stovetop with a splash of milk to bring back the creamy texture.

Broccoli casserole can also be frozen! Let the casserole cool completely, then transfer to a freezer-safe container. Freeze for up to 3 months. Thaw overnight in the refrigerator and reheat until warmed through.

Frequently Asked Questions

Can I use brown rice in this recipe?

Yes, but with a major tweak! Regular or instant brown rice absorbs liquid differently and takes significantly longer to cook than instant white rice. If using instant brown rice, you may need to extend the cook time by 30–45 minutes. Avoid using uncooked, long-grain raw brown rice entirely in this specific recipe, as it will absorb too much liquid and turn mushy before the rice fully cooks.

Can I use fresh broccoli instead of frozen?

Absolutely. Both fresh and frozen broccoli work beautifully in this casserole. If you use fresh broccoli, chop it into small, bite-sized florets. Keep in mind that fresh broccoli will retain a slightly firmer, more distinct bite, whereas frozen broccoli becomes incredibly tender and blends seamlessly into the cheesy sauce.

Why is my crockpot casserole watery, and how do I fix it?

Frozen broccoli naturally releases moisture as it thaws and cooks. If your casserole looks a bit thin when the cooking time is up, don’t panic! Stir it thoroughly and let it sit uncovered on the “Warm” setting for 15–20 minutes. The instant rice will continue to pull in the excess moisture, and the cheese sauce will thicken up beautifully as it cools slightly.

Can I make this recipe vegan?

You can easily adapt this into a plant-based comfort dish! Swap the traditional ingredients for your favorite vegan shredded cheddar, use a store-bought vegan cream of celery (or mushroom) soup, and ensure your buttery cracker topping is plant-based.

More Delicious Recipes To Try

If you love the ease and classic comfort of this cheesy slow cooker casserole, be sure to check out these other favorites from the blog:

More Cheesy Broccoli Favorites

• Homemade Cheddar Broccoli Rice-A-Roni – Skip the box! This quick one-pot stovetop side dish features tender broccoli and fluffy rice coated in a rich, velvety cheddar sauce that completely outshines the store-bought version
• Broccoli Quinoa Casserole – A wholesome, protein-packed twist on standard broccoli casserole. It’s wonderfully cheesy and comforting, but made entirely from scratch without using canned cream soups.

Effortless Slow Cooker Recipes

• Meatless Southern Green Beans In Slow Cooker – Tender green beans and potatoes are slow cooked with smoky seasonings for that authentic down home Southern flavor.
• Crockpot Southern Vegan Sweet Potato Casserole – A rich brown sugar sweetened holiday classic made entirely plant based in the crockpot.
• Meatless Southern Collard Greens In Slow Cooker – Melt-in-your-mouth collards steeped in a savory, smoky vegan potlikker that tastes like it simmered on the stove all day.

Complete Your Southern Feast

Looking for more plant-based classics to round out your holiday table or Sunday dinner? Check out our ultimate guide to Southern Vegetarian Side Dishes for everything from flawless iron skillet cornbread to vegan collard greens!

The Ultimate Easy Slow Cooker Side Dish

This crockpot broccoli rice casserole is creamy, comforting, and incredibly easy to make. Whether you need a vegetarian holiday side dish, a cozy weeknight dinner, or a simple potluck recipe, this slow cooker casserole delivers classic comfort food flavor with little effort.