Roasted Cauliflower and Brussels Sprouts

This stand-out roasted cauliflower and brussels sprouts recipe, using fresh or frozen veggies, is so simple you won't believe this delicious side dish is also healthy and oil-free. Easy to make in the oven or air fryer.

Hands down, roasting makes Brussels sprouts, cauliflower, and other vegetables tastier than any other cooking method. If you've already tried my air fryer sprouts and pomegranate or oven-roasted Brussels sprouts with grapes and balsamic, you already know how delicious they can be. 

If roasting sprouts is new to you, prepare to leave the water-logged, boiled Brussels sprouts memories behind and enjoy the ultimate flavor of these tiny cabbages.

And here's a big bonus. You get all the nutritional benefits because you don’t steam or boil away the nutrients. That's extra vitamin C and antioxidants from low-carb veggies. More flavorful AND healthier? Count me in!

Why You'll Love This Recipe

• Simple ingredients and easy prep for a savory veggie side dish you can toss in the oven or air fryer. 
• Versatile for using additional veggies, including sweet potatoes, broccoli, red pepper, and more. 
• ​A healthy recipe following plant-based diet principles, including no added oil. 
• Use fresh cauliflower and Brussels sprouts, or try my oven method for roasting frozen veggies. 

Ingredients, Notes, and Substitutions

Cauliflower. A small head of cauliflower is a good mix if you use a pound of Brussels sprouts, but the amount is your call. Cut bigger cauliflower florets in half so they cook with the Brussels sprouts.

Brussels sprouts. Use a bag of fresh sprouts, about a pound. Trim the ends and any loose or discolored outer leaves.

Onion powder. Use onion powder or onion granules to draw out the flavor of veggies. I like a ratio of twice as much onion powder as garlic powder, but you can adjust as you prefer.

Garlic powder. If you substitute garlic salt, leave the regular salt. You can always add salt after cooking.

Paprika. Use sweet paprika or smoked if you prefer that. A pinch (or more) of cayenne pepper is a great addition if you like a spicier flavor.

Black pepper. Black pepper might be all the spiciness you want. You’ll be shaking all the spices, so ½ a teaspoon goes a long way.

Salt. A small amount of sea salt or whatever's on hand helps bring out the flavor of roasted vegetables. If you are salt-free, omit it or use your favorite salt substitute.

Please see the recipe card at the bottom of this post for the complete list of ingredients with measurements plus recipe instructions.

Recipe Variations

Aside from adding veggies beyond sprouts and cauliflower, you can experiment with various spices. Substitute paprika for one of my homemade spice blends like Ethiopian Berbere spice blend, homemade chili powder, Indian garam masala, or Thai curry powder. Add a pinch of oregano or Italian mixed spices to boost the herby flavor. 

Step-by-Step Instructions

Step 1: Prepare the cauliflower florets and cut larger Brussels sprouts in half. Add them to a large bowl, then toss them with the spices. 

Step 2: Spread them out in a single layer on a baking sheet. Roast in a preheated oven for 15 minutes, toss, and roast for another 5-10 minutes. 

Air Fryer Instructions

1. Preheat the air fryer to 375 degrees, then add the cauliflower and sprouts in a single layer in the air fryer basket.
2. Cook them for 10 minutes, tossing the veggies after 5 minutes.
3. Depending on the size of your air fryer, you may need two batches. 

How to Roast Frozen Cauliflower and Brussels Sprouts

1. Spices aren't going to stick to frozen veggies until they start to cook, so I make a few adjustments when I roast frozen veg.
2. First, preheat the oven to 450 F. Arrange the veggies in a single layer. Roast for 15 minutes.
3. Remove the baking tray from the oven, then sprinkle with half the spices.
4. Flip the veggies over, adding the rest of the spices.
5. Return to the oven and continue roasting for another 5-10 minutes. 

Pro Tips

My top tip for roasting veggies in the oven or air fryer is to preheat first. It sounds simple, but it's essential for cooking the insides of veggies before the outsides are overly browned.

I recommend lining the baking sheet with parchment paper or a silicone baking mat. This reduces mess and makes the veggies easier to flip.

There's no need for a separate pan for different veggies unless you use a smaller baking tray and have an overload of veggies.

It's easiest to add the spices to a small bowl or jar and mix them up so they are equally distributed when you add them to the veggies.

Denise's Pro Tip: Transfer roasted veggies to a heated bowl to keep them warmer for longer. Cover with a light cloth or paper towel so they stay warm, but don't continue steaming.

Serving Suggestions

To jazz up this delicious side dish, sprinkle on a few fresh herbs, such as parsley, or add fresh lemon juice to compliment the spice mix. Consider a smattering of pomegranate seeds or orange zest for a festive flavor.

I highly recommend whipping up a quick batch of vegan parmesan cheese or quick hemp seed bacon bits. Added protein!

I make a complete meal by adding roasted cauliflower and sprouts over garlic mashed potatoes and smothering it with vegan mushroom gravy - it's made with white beans for added protein. 

Frequently Asked Questions