Slow Cooker Supreme Pizza Quinoa Casserole

Name: Slow Cooker Supreme Pizza Quinoa
Prep time: 5 min
Cook time: 240 min
Total time: 245 min
Ingredients: 1½ cups uncooked quinoa (rinsed well); 3 cups marinara sauce; 2 cups water or chicken broth; 1½ cups shredded mozzarella cheese (divided); ½ cup pepperoni slices; 1 cup bell peppers (diced); ½ cup onion (diced); 1 cup mushrooms (sliced); 1½ cups fresh spinach (chopped); 1 tsp Italian seasoning; ½ tsp garlic powder; ½ tsp salt; ¼ tsp black pepper; Optional: red pepper flakes or grated Parmesan for serving

ByStephanie Gigliotti May 2, 2026May 2, 2026

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If you love pizza night but want something hearty, cozy, and a little more filling, this Slow Cooker Supreme Pizza Quinoa Casserole is about to become a new favorite. It’s loaded with classic supreme pizza toppings—pepperoni, bell peppers, onions, mushrooms, and spinach—all simmered together with uncooked quinoa right in the crock pot.

Crockpot filled with a baked dish topped with melted cheese, sliced pepperoni, and chopped parsley. A small bowl of shredded cheese and scattered parsley are nearby on a striped cloth and wooden surface.

No pre-cooking, no extra pans, and no babysitting the stove. Just dump, stir, and let the slow cooker do the work.

Sometimes I’m so surprised with all the delicious things that can be made in a crock pot! Did you know you can make a Hot Fudge Chocolate Cake in the slow cooker? Or satisfying Carrot Carrot Oatmeal!? You can even make holiday candy and Peach Cobbler in your crock pot! It really is a must have appliance for me in the kitchen.

So I shouldn’t be surprised when I made fluffy, cheesy supreme style pizza quinoa in the crock pot. It’s hearty, satisfying, and full of good-for-you stuff.

Serve a big bowl of pizza quinoa alongside garlic knots, garlic toast, or a simple side salad for a full meal.

A close-up of a spoonful of cheesy, baked quinoa casserole topped with a slice of pepperoni and chopped herbs, being lifted from a dish filled with melted cheese and sauce.

Why You’ll Love This Recipe

Uses uncooked quinoa right in the slow cooker- no precooking required! So convenient! The hardest part of this recipe is rinsing the quinoa
One-pot, dump-and-go meal- I love a full meal in one! This is perfect for busy nights.
Packed with classic pizza flavor- if doesn’t get much better than pizza. Plus you can customize the toppings to what your family loves.
Great for meal prep and leftovers- Make this once and have lunch ready to go all week

🍕 Supreme Pizza Quinoa Casserole

Easy • Cozy • Family-Friendly

🛒 Ingredients

1½ cups uncooked quinoa, rinsed well
3 cups marinara sauce
2 cups water or chicken broth
1½ cups shredded mozzarella cheese, divided
½ cup pepperoni slices
1 cup bell peppers, diced
½ cup onion, diced
1 cup mushrooms, sliced
1½ cups fresh spinach, chopped
1 tsp Italian seasoning
½ tsp garlic powder
½ tsp salt
¼ tsp black pepper

✨ Optional: Red pepper flakes or grated Parmesan for serving

A cheesy, saucy serving of casserole is being lifted from a white dish, with melted cheese stretching and visible toppings like pepperoni and herbs.

How To Make Supreme Pizza Quinoa

Step 1: Prep the Slow Cooker

Lightly spray the inside of your crock pot with nonstick spray.

Step 2: Add the Base

Add uncooked quinoa (be sure to rinse it really well until the water runs clear), marinara sauce, and broth directly to the slow cooker. Stir well to combine.

Step 3: Season

Stir in Italian seasoning, garlic powder, salt, and pepper.

A white slow cooker filled with a thick, orange-red stew containing visible vegetables, beans, and grains, sitting on a wooden surface.

Step 4: Add the Toppings

Add bell peppers, onion, mushrooms, and spinach-or your favorites. Gently stir until evenly distributed.

Step 5: Cook

LOW: 4 hours- I recommend cooking this on low heat
HIGH: 2 hours- if you’re really in a pinch

The quinoa should be tender and most of the liquid absorbed. Stir once halfway through if possible.

A white slow cooker containing a layer of melted cheese and pepperoni slices over a cooked, saucy base, resembling a pizza dip. The sides of the cooker are stained with sauce.

Step 6: Add Cheese & Pepperoni

About 15–20 minutes before serving, stir in ½ cup of mozzarella. Sprinkle remaining mozzarella and pepperoni on top.

Step 7: Finish & Serve

Cover and cook until cheese is melted. Let rest 5 minutes before serving.

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A crockpot filled with a baked dish topped with melted cheese, pepperoni slices, and chopped parsley sits on a striped cloth. A bowl of shredded cheese and fresh parsley are nearby on a wooden surface.

Protein Variations

Want to mix it up? Try one of these variations:

Sausage Supreme

Add 1 lb cooked Italian sausage (crumbled) with the veggies

Ground Beef Pizza Casserole

Brown 1 lb ground beef, drain, and add before cooking

Chicken Pizza Quinoa

Stir in 2 cups cooked shredded chicken with the vegetables

Meat Lover’s Version

Use pepperoni + cooked sausage + bacon crumbles

Meal Prep & Storage

Refrigerator

Store leftovers in an airtight container for up to 4 days
Reheat in the microwave or oven

Freezer

Cool completely
Transfer to freezer-safe containers
Freeze for up to 3 months

To reheat:
Thaw overnight in the fridge and warm in the microwave or oven until heated through.

FAQ’s

Can I really use uncooked quinoa?

Yes! The slow cooker gently cooks the quinoa as it absorbs the liquid.

Do I need to rinse the quinoa?

Absolutely. Rinsing removes bitterness and improves flavor.

Will this be mushy?

No—when cooked as directed, it’s hearty and scoopable, similar to baked casserole.

Can I make this vegetarian?

Yes! Just skip the pepperoni or use plant-based pepperoni.

What size slow cooker should I use?

A 5–6 quart crock pot works best.

A wooden spoon lifts a cheesy, gooey serving of a casserole with melted mozzarella, pepperoni slices, and fresh herbs from a white dish.

More Slow Cooker Recipes You’ll Love

Healthy and Satisfying

This Slow Cooker Supreme Pizza Quinoa Casserole brings all the flavors of pizza night into an easy, comforting crock pot meal. It’s filling, family-friendly, and perfect for busy weeknights—or anytime you want pizza without turning on the oven.

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Video How To Make Supreme Pizza Quinoa

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