Southern Cheesy Yellow Squash Casserole with Buttery Ritz Crunch Step-by-step instructions

Before you start

Prepare the ingredients by washing and slicing the yellow squash into uniform rounds. Dice the sweet Vidalia onion finely to ensure it distributes evenly throughout the casserole. Grate the sharp cheddar cheese from a block to ensure optimal melting.

Preheat the oven to 375°F (190°C) to ensure it is at the correct temperature when the assembly is complete. Have all measuring tools, a mixing bowl, and your baking dish ready to go before beginning the cooking process.

Instructions

Sautéing the base

1. 1Sauté the squash and onions
   Heat 40 grams of butter in a large cast-iron skillet over medium heat. Add the sliced yellow crookneck squash and diced sweet Vidalia onion. Sauté the vegetables for 8 minutes until they soften significantly. Carefully drain any excess liquid released during the cooking process to ensure the final casserole maintains the correct texture.
   Look for The squash should be tender and the onions translucent with most liquid evaporated.
   Tip Removing excess liquid is crucial to prevent a watery casserole.

The squash and onions should be soft, fragrant, and significantly reduced in volume. Most of the moisture should have evaporated from the skillet, leaving the vegetables tender and ready for the cheese mixture.

Mixing the filling

2. 2Combine the filling
   Remove the skillet from the heat. In a separate bowl, whisk the egg and fold in the sour cream and 180 grams of sharp cheddar cheese. Incorporate this mixture into the sautéed squash and onions, stirring gently until all ingredients are evenly combined and the cheese begins to soften into the base.
   Look for The mixture should be creamy and uniform in color.
   Tip Fold gently to keep the squash slices intact.

The mixture should be thick, creamy, and well-combined. The cheese should be evenly distributed through the sour cream and egg base, creating a cohesive, velvety consistency that will bind the squash.

Baking to perfection

3. 3Top and bake
   Transfer the mixture to a baking dish. In a small bowl, toss the crushed Ritz crackers with 30 grams of melted butter and the remaining 50 grams of sharp cheddar. Sprinkle this mixture evenly over the top of the squash base. Bake at 375°F (190°C) for 25 minutes. Ensure the egg in the mixture reaches an internal temperature of 160°F (71°C) to cook it through.
   Look for The cheese should be bubbly and the cracker topping golden brown.
   Safe temperature 160°F (71°C) internal temperature (egg dishes)
   Tip Watch the crust closely in the final minutes to prevent over-browning.

The final casserole should have a vibrant, golden-brown crust that sounds crisp when tapped. The cheese should be bubbling, and the interior should feel set and firm, indicating the egg has fully cooked.

Common mistakes

Avoid overcrowding the skillet during the sauté phase, as this will cause the squash to steam rather than sauté.

If the pan is too full, cook the squash in batches. Do not skip the draining step, as excess moisture is the primary cause of a runny casserole.

Finally, ensure the butter for the topping is fully melted but cooled slightly before tossing with the crackers to prevent the crackers from becoming too soggy before baking.

How to tell it’s done

The casserole is done when the internal temperature of the egg-based custard reaches 160°F (71°C). Visually, the cheese should be bubbling vigorously around the edges of the baking dish, and the cracker topping should be a deep golden brown.

The center should be set and not liquid when gently nudged. Allow the dish to rest for 5 minutes after removing it from the oven to let the structure firm up.

• Egg dishes: 160°F (71°C) in the thickest part