Preheat oven to 350°F (175°C).

Mix crushed crackers and 1/2 cup melted butter.

Press the mixture into the bottom of a greased 2-quart baking dish to form the crust.

Melt 1/4 cup butter in a skillet over medium heat.

Add sliced onions to the skillet and saute until softened and translucent.

Pour the sauteed onions over the cracker crust in the baking dish.

Sprinkle shredded Cheddar cheese evenly over the onions.

In a separate bowl, whisk together scalded milk, beaten eggs, salt, and pepper.

Pour the milk and egg mixture over the cheese in the baking dish.

Bake in the preheated oven for 30 minutes, or until the pie is set like a custard and the top is golden brown.

Let cool slightly before serving.