The typical casserole pan is approximately 8” across and 3” to 4” deep with a tight fitting lid. But a casserole dish can be any size or shape, with or without a lid. In fact, the material the pan is made from seems to be more important to its function than its size.
Ceramic, glass and stoneware pans tend to bake a light, crispy crust around the outer edges of the food. Thick, metal pans, such as cast iron and heavy steel, seem to create a more even cooking environment and the casserole cooked in these pans will only have a crispy rim around the top outer edge. Thinner metal pans tend to be hotter on the bottom than on the edges and care must be taken to cook food in these pans at lower temperatures for slightly longer baking times to avoid burning the food on the bottom of the casserole.
Casserole dishes with lids are great for cooking foods that have a cream sauce or cheese on top. The lid prevents the loss of moisture that leaves these two foods overcooked and over dry. Glass, ceramic and stoneware casserole dishes also can be used in the microwave to cook the rice or pasta that will be part of the casserole. Using the casserole dish in this way eliminates the need to start these items in a pan on the stove and cuts down on cleanup time once the casserole is in the oven or microwave to complete the cooking process.