5g Net Carbs
Traditional squash casseroles often cook the squash twice, bury it under crackers, and lean on eggs or heavy binders to hold everything together. The result is usually more casserole than squash. This cheesy squash gratin takes a different route. Thin slices of yellow squash and sweet onion are layered in overlapping rows, much like a classic potato au gratin, then baked with cheddar, cream, and a golden browned topping. The squash stays the star, while still delivering the comfort-food experience a casserole promises. It also holds up well next to heartier mains without disappearing into the plate, which is exactly the job a good side dish is supposed to do.
Table of Contents
What Makes This Cheesy Squash Gratin Special
- Only 5g net carbs per serving
- Squash stays the star of the dish
- Sweet onion adds flavor to every bite
- No cream cheese, sour cream, or heavy binders
- Golden browned topping
- Pairs with chicken, pork, beef, or ham
- Great holiday side dish
Why This Squash Gratin Method Works
Most squash casseroles are cooked twice. The squash is softened on the stovetop, mixed into a casserole, and baked again. By the time it reaches the table, much of the texture is gone.
This squash gratin works differently. The squash is salted and drained rather than fully cooked, which pulls out excess moisture and lets it finish in the oven. The payoff is better texture, better color, and more concentrated flavor.
Layering the squash and onion in overlapping rows also adds surface area, which encourages browning and creates more of those crisp edge pieces everyone fights over.
Yellow Squash
Yellow squash is one of the most versatile summer vegetables. Its mild flavor pairs beautifully with cheese, cream, and sweet onion while staying low in carbohydrates. Smaller squash tend to have fewer seeds and a firmer texture after baking, which makes them ideal for a gratin. Look for squash that feels firm with taut, unblemished skin; older squash tends to carry more water, which works against the salting and draining step doing its job.
Sweet Onion
The onion matters as much as the squash. As the gratin bakes, the onion softens and sweetens, weaving between the squash slices and carrying flavor through the whole dish. It is the ingredient that turns a simple vegetable bake into a true comfort-food side.
Troubleshooting & Pro Tips
Gratin is watery: the squash needed more draining time.
Salting and draining is the most important step.
Topping isn’t browning: broil 1-2 minutes before serving.
Squash turned too soft: it was sliced too thin or baked too long.
Aim for slices around ¼” thick.
Using zucchini: zucchini can replace some or all of the yellow squash.
Stronger cheese flavor: use extra-sharp cheddar in place of mild or medium.
Make-Ahead, Storage & Reheating
The gratin can be assembled several hours ahead and refrigerated until ready to bake. Store leftovers covered in the refrigerator up to 4 days, in line with USDA cold storage guidance. Reheat individual portions in the microwave, or larger portions in a 350°F oven until heated through. For the best texture, reheat uncovered so the topping can crisp back up.
Serving Suggestions
This Squash Gratin pairs especially well with:
- Pot Roast
- Roast Chicken
- Pork Chops
- Ham
- Meatloaf
- Grilled Steak
- Smoked Brisket
It also earns a spot on the holiday table.
Frequently Asked Questions
Can it be frozen? It can, but squash softens after freezing and thawing, so fresh is best.
Are pork rinds required? No. They add texture and help keep carbs low, but the topping works without them.
Is this keto-friendly? Yes. At about 5g net carbs per serving, it fits most low-carb and keto plans.
Cheesy Squash Gratin
Ingredients
Gratin:
- 4 cup yellow squash ¼” thick
- 1½ cup yellow onion 2″ strips
- 2 Tbsp butter melted
- ¼ cup heavy cream
- 1 cup cheddar cheese shred
- ½ tsp black pepper
- ¼ tsp cayenne pepper
Topping:
- ½ cup pork rinds crush
- ¼ cup cheddar cheese shred
- ½ cup Parmesan grate
- 2 Tbsp butter melted
Instructions
Salt & Drain:
- Place squash in colander
- Sprinkle lightly with salt
- Drain well after 30 min
- Pat dry
Gratin:
- Combine butter, cream, cheddar, pepper, and cayenne in a bowl
- Add squash and onion, and toss until evenly coated
- Arrange in a greased 9×13″ baking dish in overlapping rows, like potatoes au gratin
Topping:
- Combine pork rinds, cheddar, Parmesan, and butter
- Sprinkle evenly over gratin
Bake:
- Bake in preheated 375°F oven 40 min until top is bubbly and brown
- Let stand a few min before serving
Notes
Arrange squash in single layer of overlapping rows; stacking layers traps moisture and softens texture.
For a browner top, broil 1-2 min before serving.
Zucchini can replace some or all of the squash.
Extra-sharp cheddar gives a stronger cheese flavor.