The Reason Your Casserole May Not Have Baked Evenly
If you don't make a lot of casseroles, your first inclination when hearing the word may be to think of zany retro recipes with combinations of ingredients that you wouldn't necessarily put together nowadays. As per The Los Angeles Times, they were an absolute staple in the 1950s, and home cooks created all kinds of variations on the standard casserole fare, some of which seem a bit bizarre to modern palates.
While they fell out of popularity for a while, there's a reason casseroles are popping up more and more on modern dinner tables — as MasterClass explains, they're reliable and not difficult to make. And, the category is very broad. Basically anything that is baked in the oven in some type of vessel counts as a casserole. There is an abundance of casserole dishes that allow you to get a tasty dinner on the table in no time at all.
However, just because they're relatively easy doesn't mean they're foolproof. There are still several common casserole mistakes you might be making. One major one, especially when you're making a relatively large or deep casserole, is getting the entire casserole baked evenly. You don't want to overcook your dish to the point where it's a mushy mess, but you also don't want any cold spots for anyone getting a plate. There's one easy rule of thumb, however, that should help you whip up mouthwatering, evenly-baked casseroles, time after time.
Cover your casserole — but not the entire time
Especially if you've topped your casserole with cheese, breadcrumbs, or something else that you want to get perfectly browned and crispy in the oven, you may be tempted to leave it uncovered the entire time it's in the oven to allow that browning and crisping to happen. Not to mention you may have had bad experiences with mushy, soupy casseroles, and figure that allowing any moisture to escape will prevent this. However, leaving your casserole uncovered is likely the culprit for issues with an uneven bake, as AllRecipes explains.
Basically, covering your casserole with a glass lid or with some aluminum foil, traps in all that heat and steam, per Survival Freedom. With all that heat circulating throughout the confines of your covered dish rather than throughout your entire oven, your casserole will bake more evenly — and, as a bonus, a little more quickly.
If you still want to get that perfectly browned top though, not to worry. To get the best of both worlds, all you have to do is remove the cover about halfway through the baking time and allow it to brown as the dish finishes baking. In situations where the casserole is baked but your topping still isn't as crispy or browned as you'd like, take Brit + Co's suggestion and set your oven to broil for a few minutes until your casserole looks picture perfect.