Keto Broccoli and Cauliflower Au Gratin with Sausage

When you’re craving comfort food but want to keep things low-carb, this Keto Broccoli and Cauliflower Au Gratin with Sausage is the perfect solution. Loaded with tender broccoli, cauliflower, smoky sausage, and an irresistibly creamy cheddar cheese sauce, this casserole delivers all the rich, satisfying flavors of a traditional au gratin without the extra carbs.

What makes this recipe truly special is that it’s more than just a side dish. Thanks to the hearty smoked sausage and generous amount of cheese, it’s a complete meal that’s filling, flavorful, and family-friendly. Whether you’re following a keto lifestyle, looking for an easy weeknight dinner, or simply love cheesy casseroles, this dish is sure to become a regular favorite.

Why You’ll Love This Recipe

• Low-carb and keto-friendly with only 6 net carbs per serving
• Rich, creamy, and loaded with cheesy flavor
• Hearty enough to serve as a complete meal
• Great for meal prep and leftovers
• Simple ingredients and easy preparation

Ingredients

• 3 cups cauliflower florets, lightly steamed – Tender, low-carb vegetable base
• 2 cups broccoli florets, lightly steamed – Adds color, texture, and nutrients
• 12 ounces smoked sausage, sliced – Provides smoky, savory flavor and protein
• 2 tablespoons butter – Creates a rich base for the sauce
• ½ onion, diced – Adds sweetness and depth
• 2 teaspoons minced garlic – Enhances the savory flavor
• 2 ounces cream cheese, softened – Creates a creamy, velvety texture
• ⅔ cup heavy whipping cream – Richens the cheese sauce
• 1½ cups shredded cheddar cheese – Delivers bold cheesy flavor
• Salt and black pepper, to taste – Enhances all the flavors

How to Make Keto Broccoli and Cauliflower Au Gratin with Sausage

Prepare the Vegetables

Preheat your oven to 350°F (175°C).

Lightly steam the cauliflower and broccoli florets until just tender. Be careful not to overcook them, as they’ll continue cooking in the oven.

Set aside while preparing the cheese sauce.

Brown the Sausage

Heat a large skillet over medium-high heat.

Add the sliced smoked sausage and cook until browned and slightly crispy around the edges.

Remove from the skillet and set aside.

Tip: Browning the sausage first adds extra flavor to the finished casserole.

Make the Cheese Sauce

In a saucepan, melt the butter over medium heat.

Add the diced onion and sauté until softened, about 4–5 minutes.

Stir in the minced garlic and cook for 30 seconds until fragrant.

Add the softened cream cheese and stir until melted and smooth.

Slowly pour in the heavy whipping cream, whisking continuously until fully combined.

Allow the mixture to simmer over medium-low heat until slightly thickened.

Add the shredded cheddar cheese and stir until completely melted and creamy.

Season with salt and pepper to taste.

Assemble the Casserole

In a large mixing bowl, combine the steamed broccoli, cauliflower, and browned sausage.

Pour the cheese sauce over the mixture and gently stir until everything is evenly coated.

Transfer the mixture to a greased 9×9-inch baking dish.

Bake

Place the casserole in the preheated oven.

Bake for 15–20 minutes, or until hot, bubbly, and lightly golden on top.

Remove from the oven and let rest for a few minutes before serving.

Tips for Success

• Steam vegetables lightly to prevent a watery casserole.
• Use freshly shredded cheese for the smoothest sauce.
• Brown the sausage well for maximum flavor.
• Let the casserole rest for 5 minutes before serving.
• Avoid overheating the cheese sauce to prevent separation.

Equipment Needed

• Large skillet
• Saucepan
• Mixing bowl
• Whisk
• 9×9-inch casserole dish
• Measuring cups and spoons
• Cutting board and knife

Recipe Variations

Spicy Keto Au Gratin

Add diced jalapeños or a pinch of red pepper flakes for extra heat.

Bacon and Cheese Version

Mix in cooked crumbled beef bacon for additional smoky flavor.

Extra Vegetable Au Gratin

Add mushrooms, spinach, or zucchini for more variety.

Different Cheese Blend

Try mozzarella, Monterey Jack, Colby Jack, or smoked cheddar for a unique flavor profile.

Serving Suggestions

This keto broccoli cauliflower au gratin pairs perfectly with:

• Grilled chicken
• Ribeye steak
• Roasted turkey
• Garlic butter shrimp
• Fresh green salad

Since it contains protein, vegetables, and cheese, it can also be served as a complete standalone meal.

FAQs

Can I make this casserole ahead of time?

Yes. Assemble the casserole up to a day in advance, cover, and refrigerate until ready to bake.

Can I freeze it?

Yes. Cool completely, wrap tightly, and freeze for up to 2 months.

How do I store leftovers?

Store leftovers in an airtight container in the refrigerator for up to 4 days.

Can I use fresh vegetables instead of frozen?

Absolutely. Fresh broccoli and cauliflower are recommended for the best texture.

What type of sausage works best?

Smoked sausage, beef sausage, turkey sausage, or your favorite fully cooked sausage all work well.

Is this recipe keto-friendly?

Yes. With approximately 6 net carbs per serving, it’s ideal for a keto or low-carb lifestyle.

Final Thoughts

This Keto Broccoli and Cauliflower Au Gratin with Sausage is everything comfort food should be—rich, creamy, cheesy, and incredibly satisfying. The combination of smoky sausage, tender vegetables, and velvety cheddar sauce creates a dish that’s both hearty and low in carbs.

Whether you’re serving it as a family dinner, bringing it to a gathering, or meal-prepping for the week, this easy keto casserole is guaranteed to be a crowd-pleaser. One bite of this cheesy goodness, and you’ll want to make it again and again.

Print