Every August I am overrun with zucchini. The neighbors are overrun with zucchini. The farmers market is overrun with zucchini. And every August, this casserole is the answer. It’s a layered, cheesy, no-fuss dinner that uses up two pounds of zucchini without anyone at the table complaining about eating their vegetables. The ground beef adds protein and makes it substantial enough for a main course, and the mozzarella gets all melty and golden on top. It’s the kind of dinner I make on autopilot when I can’t think of anything else to cook.
Why This Casserole Works
Most zucchini casseroles are side dishes. This one is a full dinner. The ground beef turns it into something hearty enough to feed a hungry family on a weeknight, and the combination of seasoned beef, tender zucchini, and lots of melted cheese hits every savory note you want. It also happens to be naturally gluten-free, which is a nice bonus if you have any dietary restrictions in your house.
The secret to a good zucchini casserole is getting rid of the excess water in the zucchini before it goes in the dish. Zucchini is over 90% water, and if you just slice it and bake it, you’ll end up with a watery puddle at the bottom of the pan. Salting the slices and letting them drain for 15 minutes solves this problem completely. It’s one extra step that makes all the difference between a sad casserole and a great one.
Choosing and Prepping the Zucchini
Look for medium-sized zucchini, about 6 to 8 inches long. The huge ones you find in late summer have bigger seeds and a more watery texture, so they’re not ideal here. If that’s all you have, slice them in half lengthwise and scoop out the seedy core before slicing. Smaller, firmer zucchini will hold their shape better in the casserole.
Slice the zucchini into ½-inch rounds. Thinner than that and they’ll disintegrate during baking; thicker and they won’t cook through. Uniform slices are important so everything cooks at the same rate. A mandoline helps if you have one, but a sharp knife and a steady hand work fine.
Building the Layers
The layering matters here. Start with a layer of the beef mixture on the bottom, then zucchini, then cheese. Repeat. The bottom layer of beef protects the zucchini from the direct heat of the dish, which helps it cook gently rather than burning. The top layer of cheese is what gets all golden and bubbly and Instagram-worthy.
I use shredded mozzarella because it melts evenly and has that classic Italian-casserole vibe. But you can swap in any good melting cheese — provolone, fontina, monterey jack, or even a mix. Just make sure it’s a melter, not a crumbly cheese like feta. Save the crumbly stuff for the top as a garnish if you want a salty contrast.
What to Serve With It
Honestly, this casserole is a complete meal on its own — protein, vegetables, dairy, all in one dish. But a simple side salad with a bright vinaigrette cuts through the richness nicely. A slice of crusty garlic bread is never wrong. If you want to stretch it further, a side of buttered pasta or rice rounds out the plate.
Leftovers reheat well in the oven at 350°F for about 15 minutes, or in the microwave for 2 to 3 minutes. The zucchini will release a little more water on the second day, but it’s still delicious. Store covered in the fridge for up to 4 days.
—Elowen Thorn
Easy Ground Beef Zucchini Casserole (40-Minute Family Dinner)
Description
A hearty, cheesy zucchini casserole made with seasoned ground beef, tender zucchini, diced tomatoes, and melted mozzarella.
Ingredients
Instructions
- Slice the zucchini into ½-inch rounds. Place the rounds in a colander over the sink, sprinkle generously with salt, and toss to coat. Let sit for 15 minutes to draw out excess moisture. Rinse well under cold water and pat dry with paper towels.
- Preheat the oven to 350°F. Heat the olive oil in a large skillet over medium-high heat. Add the onion and cook for 2 minutes until softened. Add the garlic and ground beef, breaking up the meat with a spoon, and cook until browned with no trace of pink, about 5 minutes. Drain off any excess fat.
- Stir the Italian seasoning, salt, pepper, and drained diced tomatoes into the beef mixture. Remove from heat.
- In an 8×8 baking dish, spread half of the ground beef mixture. Top with half of the zucchini slices in an even layer, then half of the mozzarella cheese. Repeat the layers with the remaining beef, zucchini, and cheese.
- Bake for 20 to 25 minutes, until the cheese is melted and beginning to brown. Let the casserole rest for 10 minutes before serving to allow the layers to set.
Notes
- Salting the zucchini and letting it drain is essential — otherwise the casserole will be watery. For a heartier version, add a layer of cooked pasta between the beef and cheese layers.
