Creamy pepper jack zucchini gratin is everything a classic gratin should be — rich, cheesy, and bubbly — with a spicy pepper jack twist. Thin zucchini and onion layers bake in a luscious cream sauce until the top turns golden. It's a show-stopping side that pairs with everything from roast chicken to seared steak.
The Ultimate Low-Carb Comfort Food
Craving a side dish that’s pure comfort but won’t derail your healthy lifestyle? Look no further! This Creamy Pepper Jack Zucchini Gratin is everything you love about a classic gratin—rich, cheesy, and bubbly—with a delightful, spicy twist. Tender slices of zucchini and onion are layered with fiery pepper jack cheese and baked in a luscious cream sauce until golden and perfect. It’s the ultimate way to transform summer squash into a show-stopping side that pairs beautifully with everything from a simple roasted chicken to a perfectly seared steak.
Ingredients
• Preparation Time: 15 minutesCooking Time: 45-50 minutesServings: 8
• 4 cups / 950g (33.5 oz) zucchini, thinly sliced (about 2-3 medium)
• 1 small yellow onion, thinly sliced
• 1½ cups / 170g (6 oz) shredded pepper jack cheese
• ½ cup / 120ml heavy whipping cream
• 2 tbsp / 28g (0.99 oz) butter
• ½ tsp garlic powder
• ¼ tsp xanthan gum
• Salt and black pepper, to taste
Instructions
1. Directions1. Get Ready to Bake: Preheat your oven to 375°F (190°C). Lightly grease a 9×9-inch or similar-sized baking dish.2. Whip Up the Spicy Cream Sauce: In a microwave-safe bowl, combine the heavy cream, butter, garlic powder, and xanthan gum. Microwave on high for 60 seconds, or until the butter has fully melted. Whisk the mixture vigorously until it’s smooth and has started to thicken.3. Build Your First Layer: Arrange one-third of the sliced zucchini and onion in an even layer across the bottom of your prepared baking dish. Season generously with salt and pepper, then sprinkle with ½ cup of the shredded pepper jack cheese.4. Keep Layering: Repeat the process, creating a second layer with another third of the zucchini and onion, another round of seasoning, and another ½ cup of cheese. Finish with a third and final layer using the remaining zucchini, onion, seasoning, and cheese.5. Pour and Perfect: Evenly pour the prepared cream sauce over the entire gratin, making sure it seeps into all the layers.6. Bake to Golden Perfection: Place the dish in the preheated oven and bake for 45-50 minutes. You’re looking for a beautifully golden-brown top and a sauce that’s bubbling happily around the edges.7. Rest Before Serving: Carefully remove the gratin from the oven and let it rest for at least 5-10 minutes. This crucial step allows the sauce to set, making it much easier to slice and serve.
Nutritional Information
• Nutrition Information(Approximate values per serving)
• Calories: 140
• Carbohydrates: 3.9g
• Protein: 5.5g
Pro Tips
• Pro-Tips for the Perfect Gratin
• To prevent a watery gratin, “sweat” the zucchini first. Toss the slices with 1 tsp (5 ml) of salt and let them sit in a colander for 20-30 minutes. Pat them completely dry with paper towels before layering.
• For perfectly even slices that cook uniformly, use a mandoline slicer for both the zucchini and the onion. Be sure to use the safety guard!
• Customize your cheese! If you’re not a fan of spice, swap the pepper jack for sharp cheddar, Gruyère, or a classic mozzarella for a milder, gooey result.
FAQ
Q: How do I prevent my zucchini gratin from being watery
A: To prevent a watery gratin, toss the zucchini slices with 1 tsp (5 ml) of salt and let them sit in a colander for 20-30 minutes to draw out moisture. Pat them completely dry with paper towels before layering.
Q: Can I use a different cheese instead of pepper jack
A: Yes, if you prefer a milder flavor, you can swap the pepper jack for sharp cheddar, Gruyère, or mozzarella for a classic, gooey result.
Q: Is this zucchini gratin recipe keto-friendly
A: Yes, this recipe is very keto-friendly. With approximately 3.9g (0.14 oz) of carbohydrates per serving, it’s an excellent low-carb side dish.
Q: What can I serve with this zucchini gratin
A: This versatile side dish pairs beautifully with a simple roasted chicken, a perfectly seared steak, or any grilled protein.
Pro Tips
- "Sweat" the zucchini first: toss the slices with 1 teaspoon of salt and let them drain in a colander for 20-30 minutes, then pat completely dry — this is what stops the gratin from turning watery.
- A mandoline gives you perfectly even zucchini and onion slices that cook uniformly (just use the safety guard).
- Make the sauce by microwaving the heavy cream, butter, garlic powder, and xanthan gum for 60 seconds, then whisk vigorously until smooth and slightly thickened.
- Build three layers of zucchini, onion, seasoning, and pepper jack, then pour the cream sauce evenly over the top so it seeps into every layer.
- Bake at 375°F / 190°C for 45-50 minutes until the top is golden and the sauce bubbles at the edges, then rest 5-10 minutes so the sauce sets for clean slicing.
Frequently Asked Questions
How do I keep my zucchini gratin from getting watery?
Salt the sliced zucchini and let it drain in a colander for 20-30 minutes, then pat it bone-dry before layering. Zucchini is over 90% water, so this step decides the whole dish.
Is this gratin keto-friendly?
Yes — each of the eight servings has about 3.9g of carbohydrates, with the sauce thickened by xanthan gum instead of flour and the richness coming from cream and pepper jack.
Can I use a different cheese?
Definitely — if you don't want the heat, swap the pepper jack for sharp cheddar, Gruyère, or mozzarella for a milder, gooey result. Shred it fresh for the smoothest melt.
Can I assemble the gratin ahead of time?
Yes — layer it up, pour over the sauce, and refrigerate for a few hours before baking. Add a few extra minutes to the bake time since it goes in cold.
Recipe card below.
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Creamy Pepper Jack Zucchini Gratin
Ingredients
Method
- Directions1. Get Ready to Bake: Preheat your oven to 375°F (190°C). Lightly grease a 9x9-inch or similar-sized baking dish. 2. Whip Up the Spicy Cream Sauce: In a microwave-safe bowl, combine the heavy cream, butter, garlic powder, and xanthan gum. Microwave on high for 60 seconds, or until the butter has fully melted.
- Whisk the mixture vigorously until it's smooth and has started to thicken. 3. Build Your First Layer: Arrange one-third of the sliced zucchini and onion in an even layer across the bottom of your prepared baking dish.
- Season generously with salt and pepper, then sprinkle with ½ cup of the shredded pepper jack cheese. 4.
- Keep Layering: Repeat the process, creating a second layer with another third of the zucchini and onion, another round of seasoning, and another ½ cup of cheese.
- Finish with a third and final layer using the remaining zucchini, onion, seasoning, and cheese. 5.
- Pour and Perfect: Evenly pour the prepared cream sauce over the entire gratin, making sure it seeps into all the layers. 6.
- Bake to Golden Perfection: Place the dish in the preheated oven and bake for 45-50 minutes. You're looking for a beautifully golden-brown top and a sauce that's bubbling happily around the edges. 7.
- Rest Before Serving: Carefully remove the gratin from the oven and let it rest for at least 5-10 minutes. This crucial step allows the sauce to set, making it much easier to slice and serve.
