Creamy Zucchini and Yellow Squash Au Gratin (Print version)
Tender zucchini and yellow squash baked in a garlic cream sauce with Parmesan and smoked gouda until golden, bubbly, and spoonable.
# Ingredients:
For the squash
01 -
1 medium zucchini, sliced 1/8 to 1/4 inch thick
02 -
1 medium yellow squash, sliced 1/8 to 1/4 inch thick
03 -
1/2 teaspoon kosher salt, plus more to taste
04 -
1/4 teaspoon black pepper
For the cream sauce
05 -
2 tablespoons (28 g) unsalted butter, plus more for the pan
06 -
1/2 small sweet onion, thinly sliced
07 -
2 large garlic cloves, minced
08 -
1 teaspoon fresh thyme leaves, or 1/4 teaspoon dried thyme
09 -
1/2 cup (120 ml) heavy cream
10 -
1/3 cup (30 g) finely grated Parmesan cheese
11 -
3/4 cup (85 g) shredded smoked gouda
# Instructions:
01 -
Preheat the oven to 425°F. Lightly butter a 9-inch oven-safe skillet or a shallow 1 1/2-quart baking dish.
02 -
Melt the butter in the skillet over medium heat. Add the onion and cook for 5-6 minutes, stirring often, until softened with lightly golden edges.
03 -
Add the garlic and thyme and cook for 1 minute. Pour in the heavy cream and simmer for 2-3 minutes, until bubbling and slightly thickened.
04 -
Stir in the Parmesan until smooth. Fold in the zucchini, yellow squash, salt, and pepper. Cook for 4-5 minutes, gently turning the slices until they begin to soften.
05 -
Spread the squash into an even layer. Sprinkle the smoked gouda over the top and bake for 15-18 minutes, until the sauce is bubbling and the cheese is golden brown.
06 -
Let the gratin rest for 5 minutes before serving. Taste and add a small pinch of salt if needed.
# Good to know:
01 -
Best with small to medium summer squash, which release less water than oversized squash.
02 -
Use a shallow skillet or baking dish so the top browns and excess moisture can cook off.
03 -
Leftovers keep refrigerated for up to 3 days.