Active Time

　　1 hour

　　Total Time

　　1 hour 30 minutes

　　Golden, creamy squash casserole is a classic Southern side dish, found at beloved meat-and- three restaurants and many family potlucks. It’s a fantastic way to use up summer squash—especially at the height of the summer, when everyone’s garden seems to produce way too much—and it’s delicious enough to keep everyone coming back for seconds. This version skips the cheddar cheese, Ritz crackers, and eggs that you find in some squash casserole recipes. Instead, we let the sweet flavor of the vegetables stand out in a simple white sauce made with melted butter and broth, with a bit of flour to thicken everything and some sour cream to add body. (If you have a bumper crop of zucchini in your garden, you could substitute it for some of the yellow squash.)

　　The key to keeping a squash casserole from getting watery while it bakes is to precook the veggies in order to remove some of their moisture. While many recipes ask you to sauté the ingredients, we prefer to roast the squash with just a bit of oil and some seasoning. It requires less work than standing over the stove during the prep time and really improves the texture of the finished dish. Then all you have to do is pour everything into a casserole dish, add a topping of breadcrumbs, and bake until the filling is bubbling and the top is crispy and golden brown. Serve the summer squash casserole with pork chops or any dish you’ve made on your smoker.

　　

Ingredients

12 servings

　　4 lb. yellow squash (10 medium), trimmed, halved lengthwise, and sliced crosswise ⅛" thick

　　¼ cup vegetable oil

　　2 tsp. kosher salt

　　2 tsp. freshly ground black pepper

　　2 medium onions, chopped (2 cups)

　　1 green bell pepper, chopped

　　1 red bell pepper, chopped

　　7 Tbsp. unsalted butter

　　4 slices firm white sandwich bread with crust, coarsely ground in a food processor (about 2¼ cups)

　　¼ cup all-purpose flour

　　1¾ cups reduced-sodium chicken broth (14 oz.)

　　1 cup sour cream

　　

Step 1

Put oven rack in lower third of oven and put a large shallow baking pan on rack, then preheat oven to 475°F.

　　

Step 2

Toss one-third of squash with 1 Tbsp. oil, ½ tsp. salt, and ½ tsp. pepper in a bowl, then spread in preheated baking pan in 1 layer and roast in oven, stirring once, until tender, 12–15 minutes. Transfer squash to a large bowl. Roast remaining squash in 2 batches in same manner, tossing with 1 Tbsp. oil, ½ tsp. salt, and ½ tsp. pepper (per batch) just before roasting and adding to bowl when done.

　　

Step 3

Toss onions and bell peppers with remaining 1 Tbsp. oil, remaining ½ tsp. salt, and remaining ½ tsp. pepper in another large bowl, then spread in baking pan and roast, stirring once, until onions are golden, 8–10 minutes. Transfer to bowl with squash.

　　

Step 4

Move oven rack to middle position and reduce oven temperature to 400°F.

　　

Step 5

Melt 3 Tbsp. butter in a saucepan and remove from heat, then add breadcrumbs and a pinch of salt, tossing to coat breadcrumbs. Spread evenly in cleaned baking pan and bake, without stirring, until pale golden, about 5 minutes.

　　

Step 6

Melt remaining 4 Tbsp. butter in a 3-qt. heavy saucepan over moderately low heat, then whisk in flour and cook roux, whisking constantly, 3 minutes. Add broth, whisking, and bring to a boil, whisking. Reduce heat and simmer, whisking occasionally, 3 minutes. Remove from heat and cool 5 minutes, whisking occasionally, then whisk in sour cream and salt and pepper to taste. Pour sauce over squash mixture and stir gently until combined well.

　　

Step 7

Butter a 13x9" glass or ceramic baking dish (3-qt. capacity), then spread squash mixture evenly into it and sprinkle with bread crumbs. Bake casserole until golden and bubbling, 15–20 minutes. Serve immediately.

　　Do Ahead: Casserole (without breadcrumbs) can be assembled 1 day ahead and cooled completely, uncovered, then chilled, covered tightly with plastic wrap. Let stand at room temperature 1 hour before sprinkling with breadcrumbs and baking. 

　　Editor’s note: This recipe was originally published in the September 2005 issue of ‘Gourmet’ and first appeared on Epicurious in August 2005. Head this way for more of our best casserole recipes →

　　Cook’s Note

　　Resist the temptation to toss together all the squash with the oil, salt, and pepper. If you don’t do it in batches, as noted in the recipe, the salt will draw out too much liquid from the squash waiting to be roasted, and the casserole will be soupy.