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Cheesy Zucchini and Ground Beef Casserole Recipe
Ash Tyrrell

Cheesy Zucchini and Ground Beef Casserole Recipe

I made this casserole for the first time on a night when my fridge was overflowing with zucchini and I had zero energy for a complicated dinner. One skillet, forty-five minutes, and I had a bubbling, cheesy dish that my whole family fought over. Now I make it almost every week during zucchini season because it's that good and that easy
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Total Time 45 minutes
Servings: 8
Ingredients Method Notes

Ingredients
  

  • 3 cups zucchini thinly sliced – slicing it evenly (I like using a mandoline) helps every piece cook at the same rate
  • 1/4 teaspoon sea salt – used to draw moisture out of the zucchini so your casserole doesn't turn watery
  • 1 pound ground beef – go for 80/20 for the best flavor since leaner beef can dry out in the oven
  • 2 cloves garlic finely minced – fresh garlic makes a noticeably bigger flavor difference than the jarred stuff
  • 1/2 cup onion finely diced – yellow onion works great here and cooks down soft and sweet
  • 2 1/2 cups prepared marinara sauce – a good store-bought jar is totally fine just look for one that's about 20 ounces
  • 1 teaspoon dried basil – adds that classic Italian aroma without needing fresh herbs on hand
  • 1/4 teaspoon dried oregano – a small amount goes a long way and rounds out the sauce
  • 1/4 cup heavy cream optional – stir this in for a creamier, richer sauce, but it's easy to skip
  • 1 1/2 cups shredded mozzarella divided – buy a block and shred it yourself, since fresh-shredded cheese melts smoother than the bagged kind
  • 1/2 cup shredded Parmesan – freshly grated Parmesan browns beautifully on top and has way more flavor than the pre-shredded jar

Method
 

  1. Start by preheating your oven to 350°F so it's ready when you are. Slice the zucchini thinly and lay the rounds out on a clean kitchen towel, then sprinkle them evenly with the sea salt. Cover with another towel and set something heavy on top, like a Dutch oven, to press out the excess moisture.
  2. While the zucchini rests, add the ground beef to your braiser pan or skillet over medium heat and cook until it's almost done. Toss in the minced garlic and diced onion once the beef is nearly browned, and cook for another minute or two until fragrant. Drain off any excess grease before moving on.
  3. Pour in the marinara sauce along with the dried basil and oregano, stirring everything together over medium heat. If you're using the heavy cream, slowly stir it in now for a richer sauce. Let it all simmer gently for about two minutes so the flavors meld.
  4. Scoop out roughly two-thirds of the sauce into a separate bowl and set it aside for layering later. This step is what creates those distinct cheesy layers instead of one mushy mixture. Leave the remaining third of the sauce in the pan as your base layer.
  5. Arrange half of the pressed zucchini slices over the sauce left in the pan, then sprinkle on half of the mozzarella. Spoon the reserved sauce evenly over that layer so every bite gets coated. This is where the casserole really starts taking shape.
  6. Top everything with the remaining zucchini slices, the rest of the mozzarella, and all of the Parmesan cheese. Spread it out evenly so the cheese melts uniformly across the top. This top layer is what turns golden and bubbly in the oven.
  7. Slide the pan into your preheated oven and bake for 25 to 30 minutes, until the cheese is lightly browned and the sauce is bubbling around the edges. Pull it out and let it rest for 5 to 10 minutes before serving. This resting time helps the layers set so you get clean scoops.

Notes

  • I never skip pressing the zucchini, since it's the single biggest reason this dish can turn watery if you rush it
  • I like to shred my own cheese instead of using pre-shredded bags, because it melts so much smoother and coats every layer better
  • If I don't have a braiser pan, I brown everything in a skillet first and then transfer it to a 9x13 dish, which works just as well
  • I always taste my marinara before adding it, since some jarred sauces are already salty and I don't want to over-salt the dish
  • Letting it rest before serving really does matter to me, because cutting in too soon makes the layers slide apart