Try this Cheesy Zucchini Squash Au Gratin Bake Recipe.
Traditional potato gratins rely on starch released by the tubers to thicken heavy cream during a long bake, whereas summer squash variants require preemptive sauce reduction because zucchini and yellow squash release high volumes of water when heated. Controlling moisture determines whether the final dish holds together or swims in liquid.
Fresh vegetables contain significantly more water than preserved or frozen alternatives, meaning fresh zucchini slices require careful layering to allow proper steam escape during the baking window. Allowing the casserole to rest for five minutes off the heat lets the dairy fats re-solidify slightly for clean portioning.