Ingredients & Substitutions
Here I explain the best ingredients for my chicken zucchini casserole recipe, what each one does, and substitution options. For measurements, see the recipe card.
How To Make Chicken Zucchini Casserole
I have step-by-step photos here to help you visualize the recipe. For full instructions with amounts and temperatures, see the recipe card. I didn’t add garlic in my casserole, but feel free to add 2-4 cloves of minced garlic—just sauté them with the onions and mushrooms.
Storage & Meal Prep
Store: Keep leftovers in an airtight container in the refrigerator for up to 3-4 days. The veggies do get more mushy, but the flavor is still great. Meal prep: This chicken and zucchini casserole does have several steps, but it’s a breeze if you prep ahead! You can either just do the chopping in advance, or assemble the whole thing and keep it in the fridge (for 1-2 days) until ready to bake. Reheat: Just pop it in the oven for 15-20 minutes at 350 degrees F. The microwave works for individual portions if you’re in a hurry. Freeze: The assembled casserole freezes well for up to 3 months. You can reheat it from frozen at 350 degrees F, but this takes a long time (at least 45 minutes), so I usually thaw it in the fridge overnight for quicker heating.
More Cheesy Casserole Recipes
If you’re a fan of easy, cheesy casseroles like this, you’ll love my others:
I’ve been making this chicken zucchini casserole since 2018, but I made some tweaks to the recipe recently to improve it. And I discovered some additional tips along the way:
Browning and stovetop temp depends on your pan. I use cast iron and sometimes need to turn it down, but with nonstick you may need the heat even higher. Use lower heat if you don’t want your chicken to darken. I like mine golden, but you can choose medium heat if you like less browning. It’s important to cook down the zucchini and mushrooms enough and let all the liquid evaporate. If you don’t, the casserole will be watery. If the zucchini starts to brown too much, reduce heat to medium but continue cooking to get it tender. If it’s crisp, it will release water when you bake the chicken zucchini casserole. Drain the chicken and veggies if needed. Sometimes the veggies still release more moisture as they sit while I make the sauce. If this happens, drain them again before mixing in the sauce. Save time by multitasking. I cut the zucchini while the mushrooms and onions cook, then make the Gruyere cheese sauce while the oven preheats. Do not use a whisk to mix in the shredded cheese. The cheese will clump on the whisk. I’ve found that a wooden spoon works best for this. Salt the sauce to taste. I didn’t need additional salt in the sauce, but this will vary depending on the broth and cheese brands you use.
Tools I Use For This Recipe
Casserole Dish – My favorite brand. This one is a little smaller than your standard baking dish, but it’s the perfect size for this recipe. You can use a larger one, but it will be less full. Cast Iron Skillet – You need a big skillet to fit all those veggies before they cook down! And I love my cast iron for the best browning and evaporating extra moisture.
Please enter your first name for your account. Your saved recipe will also be sent to your email. This time, a group of my girl friends all went together for a relaxing weekend. And unlike most of our family trips that are pretty planned out, we just did whatever we felt like last-minute. It was just what I needed — even if it meant coming back to a 12-hour recipe photo shoot the next day. 😉 I did bring back a “lovely” sunburn, because clearly I underestimated the California sun with my SPF. It was worth it.
