Name: Zucchini & Yellow Squash Au Gratin | Keto, Low-Carb Recipe
Prep time: 15 min
Cook time: 20 min
Total time: 35 min
Cuisine: French
Ingredients: 2 Large Zucchini Squash, sliced; 2 Large Yellow Squash, sliced; 3/4 Cup Unsweetened/Unflavored Almond Milk; 2 Cups Smoked Gouda, grated; 1 tbsp. Butter; 1/2 tsp Kosher Salt; 1/2 tsp. Garlic Powder; 1/2 tsp. Black Pepper, ground; Leaves from 3 Rosemary Sprigs, chopped, plus more for garnish; 2 teaspoons Fresh Thyme, Chopped; 1 Cup Sharp Cheddar, shredded

Jump to Recipe

If you’re on the hunt for a side dish that’s rich, flavorful, and destined to win over even the pickiest eaters, let me introduce you to Zucchini & Yellow Squash Au Gratin | Keto, Low-Carb. This is not your average casserole — think smoky Gouda, golden cheddar, and fresh herbs bubbling into tender squash for a decadent yet waistline-friendly bake. It’s lush enough for holiday dinners, but simple enough to become your go-to veggie upgrade.

Zucchini & Yellow Squash Au Gratin | Keto, Low-Carb Recipe - Recipe Image

Ingredients You’ll Need

The secret to a show-stopping Zucchini & Yellow Squash Au Gratin | Keto, Low-Carb lies in a short ingredient list packed with flavor and creamy texture. Each item here brings out the natural beauty of the summer squash while ensuring that every bite is anything but boring.

Zucchini Squash: Choose firm, glossy green zucchinis—the dark color means there’s plenty of sweetness and snap.
Yellow Squash: Their sunny color looks beautiful and their mild, buttery flavor makes this dish a true crowd-pleaser.
Unsweetened/Unflavored Almond Milk: Keeps the dish creamy and light, with no extra carbs or sweetness.
Smoked Gouda: This cheese infuses a fabulous smoky depth that makes the gratin irresistible.
Butter: Just a touch to enrich the sauce and bring everything together with a glossy finish.
Kosher Salt: Essential for bringing out the natural flavors—don’t skip it!
Garlic Powder: Adds a subtle warmth and depth without overwhelming the vegetables.
Ground Black Pepper: A little kick to lift all the creamy and cheesy notes.
Fresh Rosemary: Chopped rosemary perfumes the gratin and is gorgeous both in the sauce and as a standout garnish.
Fresh Thyme: Brings brightness and complexity to round out the herb profile.
Sharp Cheddar Cheese: Melty and bold, the cheddar gives the golden crust its savory richness.

How to Make Zucchini & Yellow Squash Au Gratin | Keto, Low-Carb

Step 1: Preheat Your Oven

Start by preheating your oven to 400° F. A good, hot oven ensures that your Zucchini & Yellow Squash Au Gratin | Keto, Low-Carb will bake up bubbly and beautifully golden on top. Getting the temperature just right is the secret to a luscious, creamy interior and a perfectly crisped cheese topping.

Step 2: Prep the Squash

Give your zucchini and yellow squash a good rinse, then slice each vegetable into even 1/4-inch rounds. The uniform thickness helps them bake evenly, so every slice ends up tender—not mushy or crunchy. Once sliced, arrange the veggies in your favorite baking dish—you can layer them in neat overlapping rows for a pretty presentation, or scatter them in for a rustic look.

Step 3: Build That Dreamy Cheese Sauce

In a medium saucepan set over medium heat, combine the almond milk, grated smoked Gouda, butter, kosher salt, garlic powder, black pepper, chopped rosemary, and thyme. Stir everything together until the cheese melts completely and the mixture is smooth and creamy. This sauce will be the backbone of your Zucchini & Yellow Squash Au Gratin | Keto, Low-Carb, giving every bite the perfect amount of herby richness and smoky flair.

Step 4: Pour and Assemble

Carefully pour the velvety cheese and herb mixture over the arranged squash, making sure the sauce seeps all the way to the bottom and covers every piece. Be generous—the more evenly you distribute the sauce, the more luscious every forkful will taste!

Step 5: Top with Cheddar and Herbs

Sprinkle the shredded sharp cheddar cheese evenly over the top of the dish. Add a few extra rosemary leaves here if you like a little extra herbal aroma wafting up as it bakes. The cheddar will form that irresistible molten golden layer that defines a true au gratin.

Step 6: Bake Until Golden

Slide your baking dish into the preheated oven and let the magic happen! In about 20 minutes, you’ll have a bubbling dish that’s golden and gloriously aromatic. The top should be a lovely golden brown and the sides will be sizzling. Let the Zucchini & Yellow Squash Au Gratin | Keto, Low-Carb sit for a few minutes before serving—this helps everything set for cleaner slices.

How to Serve Zucchini & Yellow Squash Au Gratin | Keto, Low-Carb

Garnishes

A handful of fresh chopped rosemary or a sprig of thyme on top right before serving is both delicious and eye-catching. For a splash of color, try a sprinkle of finely chopped parsley or chives. The extra herbs boost flavor, while the vibrant greens make your Zucchini & Yellow Squash Au Gratin | Keto, Low-Carb especially inviting at the table.

Side Dishes

Pair your gratin with a crisp green salad for balance, or serve alongside roasted meats like chicken, steak, or pork for a complete keto meal. It’s divine as a part of a brunch buffet too—just add a platter of bacon or smoked salmon for pure indulgence.

Creative Ways to Present

Individual ramekins turn this dish into an elegant starter or a personal side. If you’re hosting a special dinner, try alternating the zucchini and squash slices vertically in a spiral for a stunning visual effect—guests will think you spent hours on it! The leftovers even make a wonderful filling for a breakfast omelette or a layered veggie bowl.

Make Ahead and Storage

Storing Leftovers

Leftover Zucchini & Yellow Squash Au Gratin | Keto, Low-Carb keeps beautifully in the fridge. Cover the dish tightly with foil or transfer to an airtight container and store for up to three days. The flavors only deepen as it sits, making tomorrow’s lunch seriously irresistible.

Freezing

While the gratin can technically be frozen, the texture of the squash may get softer after thawing. If you do want to freeze it, cool the dish completely and wrap it well. It’s best to enjoy within one month for maximum freshness and flavor—but remember to thaw in the fridge overnight before reheating.

Reheating

To reheat, pop your gratin into a 350° F oven, covered loosely with foil, until warmed through (about 15-20 minutes). If reheating a single portion, the microwave works in a pinch—just keep an eye to avoid overheating so the cheese sauce stays creamy and delicious.

FAQs

Can I use other types of cheese in this recipe?

Absolutely! While smoked Gouda and sharp cheddar give a signature flavor to Zucchini & Yellow Squash Au Gratin | Keto, Low-Carb, you can experiment with Gruyère, Swiss, or even mozzarella for a different twist. Just choose cheeses that melt well.

Do I have to use almond milk?

Almond milk keeps this gratin keto and dairy-light, but any low-carb, unsweetened milk alternative will work—coconut or macadamia milk are great, too. Avoid anything sweetened or flavored for the best results.

Is it okay to prepare this dish ahead of time?

Definitely! You can assemble the gratin a day in advance, keep it covered in the refrigerator, then pop it straight into the oven when you’re ready. It’s perfect for stress-free entertaining or make-ahead meal prep.

Can I make Zucchini & Yellow Squash Au Gratin | Keto, Low-Carb without fresh herbs?

Fresh is best for flavor, but in a pinch, you can substitute half the amounts of dried rosemary and thyme. Start with less, taste, and adjust, as dried herbs are more potent than fresh.

How do I keep my gratin from getting watery?

To avoid excess liquid, slice your squash evenly and don’t overcrowd the baking dish. If your squash is especially juicy, you can very lightly salt the slices and let them sit to draw out extra moisture before assembling the dish.

Final Thoughts

If you’re ready to fall in love with your veggies all over again, Zucchini & Yellow Squash Au Gratin | Keto, Low-Carb will absolutely do the trick. It’s creamy, herby, deeply satisfying, and totally doable on a busy weeknight. Give it a shot—your next meal might just become a family favorite!

Zucchini & Yellow Squash Au Gratin | Keto, Low-Carb Recipe

★★★★★

5 from 18 reviews

Author: Ella
Total Time: 35 minutes
Yield: 6 servings 1x
Diet: Vegetarian

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Description

This Zucchini & Yellow Squash Au Gratin is a delicious and creamy low-carb dish that is perfect for a keto-friendly meal. Layers of thinly sliced zucchini and yellow squash are smothered in a rich, cheesy sauce and baked to golden perfection. A comforting and satisfying side dish or vegetarian main course.

Instructions

Preheat oven to 400°F: Get the oven ready for baking.
Prepare the Squash: Wash and slice the zucchini and yellow squash, then arrange them in a baking dish.
Make the Cheese Sauce: In a saucepan, combine almond milk, smoked Gouda, butter, salt, garlic powder, black pepper, rosemary, and thyme. Cook until a smooth sauce forms.
Assemble: Pour the cheese sauce over the squash in the baking dish.
Add Cheese Topping: Sprinkle cheddar cheese over the top, and garnish with rosemary.
Bake: Bake the gratin for 20 minutes or until golden brown.