1 tablespoon olive oil
2 tablespoons unsalted butter, plus more for greasing the casserole dish
4 cups thinly sliced leeks
2 cloves garlic, minced
1 1/2 teaspoons herbes de Provence
1/2 teaspoon kosher salt
½ teaspoon freshly ground pepper
1 cup heavy cream
1/2 cup grated parmesan cheese
4 medium zucchini cut into ¼-inch coins
1 ½ cups (6 ounces) grated sharp Cheddar cheese
Let’s get started. Grease a 1-quart casserole dish with a little butter – I use my slightly smaller Le Creuset 24-ounce casserole dish – and preheat the oven to 400 degrees F.
Melt the butter in the oil in a large skillet over medium heat.
Add the leeks, garlic, herbes de Provence, salt, and pepper. Stir to coat with the fat and saute for 10 minutes, stirring occasionally. If the leeks begin to brown, reduce the heat a smidge.
Add the cream, bring to a boil, reduce the heat to a gentle boil, and cook until the cream is quite thick, about 6 or 7 minutes. When you run a spoon through the cream, it stays in place.
Stir in the Parmesan cheese.
Spread ¼ of the cream and leeks on the bottom of the greased casserole dish.
Lay ¼ of the zucchini slices on the bottom, overlapping slightly.
Repeat layering the cream and leek mixture and the zucchini 3 more times.
Strew the shredded Cheddar cheese over the top and bake in preheated oven for 40 minutes.
Let sit for 10 minutes to settle before serving.
The casserole can be prepared a day before cooking. Cover and refrigerate. Take out of the refrigerator and place in preheated oven; increase cooking time by 10 minutes.
Keywords: casserole, side dish, leek, zucchini, cheddar cheese, Parmesan cheese, Herbes de Provence, gluten-free