Side Dish: United States – Oklahoma, Southern Plains United States – Oklahoma Squash Casserole

Food safety reminder: Follow safe food-handling practices and use a food thermometer to verify safe internal cooking temperatures.

Serving Size: 6

Approximate Time

Prep 25 min

Cook 30 min

Additional 10 min

Total 1 hr 5 min

Ingredients

- 2 lb (900 g) yellow squash, trimmed and thinly sliced (about 1/4-inch / 6 mm)
- 1 medium yellow onion, finely chopped (about 6 oz / 170 g)
- 5 tbsp (70 g) unsalted butter, divided (3 tbsp for cooking, 2 tbsp for topping)
- 1 cup (113 g) shredded sharp cheddar cheese
- 2 large eggs (approx. 100 g), lightly beaten
- 1/2 cup (120 ml) whole milk
- 1/4 cup (30 g) all-purpose flour
- 1 tsp (5 g) kosher salt
- 1/2 tsp (1 g) freshly ground black pepper
- 1 cup (60 g) crushed buttery crackers (about 20–25 Ritz crackers) or 1 cup (100 g) plain breadcrumbs
- 1 tbsp (15 g) chopped fresh parsley (optional, for garnish)

Instructions

Short Description:
A creamy, cheesy casserole of sliced yellow squash and onions bound with eggs and milk, finished with a buttery crushed-cracker topping and baked until golden and bubbly. A classic Oklahoma side to serve with roasted meats or Sunday dinner.

Regional Notes:
This Oklahoma version highlights yellow squash and sautéed onions mixed with sharp cheddar, then finished with a buttery crushed-cracker (or breadcrumb) topping — the hallmark that distinguishes it from other regional squash casseroles. The cracker topping and simple egg-milk binder reflect home-cooked Southern Plains pantry traditions.

1. Preheat the oven to 350°F (175°C). Grease a 2-quart (about 2 L) casserole dish or a 9x9-inch (23x23 cm) square baking pan.
2. Melt 3 tbsp (42 g) of the butter in a large skillet over medium heat. Add the chopped onion and sauté until translucent, about 5–7 minutes.
3. Add the sliced yellow squash to the skillet, season with 1/2 tsp (2.5 g) of the salt and 1/4 tsp (0.5 g) of the pepper, and cook, stirring occasionally, until the squash is just tender and much of the excess moisture has evaporated, about 8–10 minutes. Remove from heat and let cool slightly.
4. In a large bowl whisk together the eggs, milk, flour, remaining 1/2 tsp (2.5 g) salt, and remaining 1/4 tsp (0.5 g) pepper until smooth. Stir in the shredded cheddar cheese, then fold in the sautéed squash and onions until evenly combined.
5. Transfer the squash mixture to the prepared casserole dish and smooth the top with a spatula.
6. In a small bowl combine the crushed buttery crackers (or breadcrumbs) with the remaining 2 tbsp (28 g) melted butter until the crumbs are evenly moistened. Sprinkle the crumb mixture evenly over the top of the casserole.
7. Bake in the preheated oven until the topping is golden-brown and the casserole is set and bubbling at the edges, 25–30 minutes. If the topping browns too quickly, tent loosely with foil for the last 5–10 minutes.
8. Remove from the oven and let rest 5–10 minutes before serving. Garnish with chopped fresh parsley if desired. Serve warm as a side dish.