Tasty Potato and Shredded Zucchini Casserole

I’ll be honest—I used to think casseroles were what you made when you had a bunch of random leftovers and no real dinner plan. They seemed like the lazy cook’s way out, you know? Then I realized casseroles are actually genius because they let you throw together simple ingredients and end up with something that feeds the whole family without much fuss.

This potato and zucchini casserole is one of those recipes that looks like you put in way more effort than you actually did. The secret is in the crispy Panko topping—it gives you that satisfying crunch while the cheesy potato base stays creamy underneath. Plus, sneaking shredded zucchini into a dish like this is an easy way to get vegetables on the table without anyone complaining about it.

What Kind of Zucchini Should I Use?

Any fresh zucchini from your grocery store or garden will work great for this casserole. Medium-sized zucchinis are ideal because they’re easier to shred and tend to have fewer seeds than the really large ones. If you end up with bigger zucchinis, that’s totally fine – just be aware they might release a bit more moisture during cooking. After shredding your zucchini, you can place it in a clean kitchen towel and give it a good squeeze to remove excess water, which will help keep your casserole from getting watery. Some people prefer leaving the skin on for extra color and nutrients, but you can peel it if you’d rather have a more uniform look.

Options for Substitutions

This casserole is pretty forgiving when it comes to swapping ingredients:

• Progresso Creamy Three Cheese Cooking Sauce: If you can’t find this specific sauce, make your own by mixing 1 cup of heavy cream with ½ cup of grated parmesan and a pinch of garlic powder. You could also use a can of cream of mushroom or cream of chicken soup in a pinch.
• Sharp cheddar cheese: Any good melting cheese works here – try Monterey Jack, Colby, or a Mexican cheese blend. You can also mix in some mozzarella for extra stretchiness.
• Frozen hashbrown potatoes: Fresh potatoes work great too. Just peel and shred about 2 pounds of russet or Yukon gold potatoes. Make sure to squeeze out excess moisture with a clean kitchen towel before using.
• Zucchini: Yellow squash is basically interchangeable with zucchini here. Just shred it the same way and squeeze out the extra water before adding to the casserole.
• Panko bread crumbs: Regular bread crumbs work fine, or you can make your own by toasting a few slices of bread and crushing them up. Crushed crackers like Ritz also make a tasty topping.
• Sour cream: Greek yogurt is a solid swap for sour cream and adds a bit more protein. Just use the full-fat version to keep that creamy texture.

Watch Out for These Mistakes While Baking

The biggest mistake when making this casserole is forgetting to squeeze out excess moisture from the shredded zucchini, which can leave you with a watery, soupy dish instead of a creamy casserole – just wrap the shredded zucchini in a clean kitchen towel and twist it over the sink until no more liquid comes out.

Another common error is skipping the step of letting the cheese sauce bubble before adding the vegetables, as this helps thicken the mixture and prevents a runny final product.

To get a golden, crispy topping instead of pale, soft breadcrumbs, make sure your butter is fully melted and evenly mixed with the panko, and if the top starts browning too quickly during baking, simply cover it loosely with foil for the remaining time.

Finally, resist the urge to dig in right away – letting the casserole rest for 10-15 minutes after baking allows it to set up properly and makes serving much cleaner.

What to Serve With Potato and Zucchini Casserole?

This cheesy casserole is pretty hearty on its own, so I like to serve it alongside something fresh and light to balance things out. A simple mixed greens salad with a tangy vinaigrette cuts through all that creamy goodness perfectly, or you could go with roasted green beans or steamed broccoli if you want a warm veggie side. Since this casserole works great as a side dish too, it pairs really well with grilled chicken, pork chops, or even a basic meatloaf for a complete dinner. If you’re serving it for brunch, add some scrambled eggs and crispy bacon to round out the meal.

Storage Instructions

Store: Keep any leftover casserole covered tightly with foil or in an airtight container in the fridge for up to 4 days. The flavors actually meld together nicely overnight, so it tastes great as leftovers throughout the week.

Freeze: This casserole freezes really well, either before or after baking. If freezing unbaked, assemble everything except the panko topping, wrap tightly, and freeze for up to 3 months. For already-baked casserole, let it cool completely, then wrap well and freeze for up to 2 months.

Reheat: Warm up individual portions in the microwave for about 2 minutes, or reheat the whole casserole covered with foil at 350°F for 20-25 minutes until heated through. If reheating from frozen, thaw in the fridge overnight first for best results.

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 2700-3000
• Protein: 65-75 g
• Fat: 170-190 g
• Carbohydrates: 230-260 g

Ingredients

For the main dish:

• 1/4 cup butter
• 5 green onions, sliced
• 1 1/4 cups sour cream
• 18 oz cheese sauce
• 2 cups sharp cheddar (shredded from the block)
• 2 large zucchinis (shredded and squeezed dry)
• 6 cups potatoes (peeled and cut into 1/2-inch cubes)

For the topping:

• 1/4 cup butter (melted)
• 1 3/4 cups Panko bread crumbs
• 1/2 teaspoon garlic powder
• 1/4 teaspoon smoked paprika

Step 1: Prep Vegetables and Preheat Oven

• 6 cups potatoes
• 2 large zucchinis

Peel and cut potatoes into 1/2-inch cubes, then place in a bowl of cold water to prevent browning.

Shred the zucchinis using a box grater or food processor, then wrap them tightly in a clean kitchen towel and squeeze firmly to remove excess moisture—this is crucial for preventing a watery casserole.

Preheat your oven to 350°F while you prepare the remaining ingredients.

Step 2: Build the Cheese Sauce Base

• 1/4 cup butter
• 5 green onions, sliced
• 1 1/4 cups sour cream
• 18 oz cheese sauce
• 2 cups sharp cheddar

Melt 1/4 cup butter in a large skillet over medium heat, then add the sliced green onions and cook for about 2 minutes until fragrant and slightly softened.

Pour in the sour cream and cheese sauce, stirring constantly until the mixture begins to bubble.

Add the shredded cheddar cheese and stir until completely melted and smooth—the sauce should be creamy and cohesive at this point.

Step 3: Combine and Assemble the Casserole

• potatoes from Step 1
• zucchini from Step 1
• cheese sauce mixture from Step 2

Drain the potatoes from their cold water and pat them dry with paper towels to remove excess moisture.

Fold the drained potatoes and squeezed zucchini from Step 1 into the cheese sauce from Step 2, stirring gently but thoroughly until all vegetables are evenly coated.

Pour the mixture into a 9×13 inch baking dish, spreading it into an even layer.

I like to do a quick taste test of the sauce mixture at this point and add a pinch of salt if needed, since the vegetables will release some liquid as they cook.

Step 4: Create and Top with Breadcrumb Crust

• 1/4 cup butter
• 1 3/4 cups Panko bread crumbs
• 1/2 teaspoon garlic powder
• 1/4 teaspoon smoked paprika

In a small bowl, combine the melted butter with the Panko bread crumbs, garlic powder, and smoked paprika, mixing until the breadcrumbs are evenly coated and have a slightly damp texture.

Sprinkle this mixture evenly over the top of the casserole, pressing it gently so it adheres to the surface—this creates a delicious golden crust as it bakes.

Step 5: Bake and Cool the Casserole

Bake in the preheated 350°F oven for 45-50 minutes until the top is golden brown and the edges are bubbling slightly.

The casserole will be piping hot, so let it rest for at least 10 minutes before serving—I find this helps the casserole set up and makes it easier to cut into clean portions.

You can serve it warm or at room temperature depending on your preference.

Tasty Potato and Shredded Zucchini Casserole

Delicious Tasty Potato and Shredded Zucchini Casserole recipe with step-by-step instructions.

Print Recipe Pin Recipe

Prep Time 25 minutes mins

Cook Time 45 minutes mins

Total Time 1 hour hr 12 minutes mins

Servings: 8 servings

Calories: 2850

Ingredients Method

Ingredients

  

For the main dish:

• 1/4 cup butter
• 5 green onions, sliced
• 1 1/4 cups sour cream
• 18 oz cheese sauce
• 2 cups sharp cheddar (shredded from the block)
• 2 large zucchinis (shredded and squeezed dry)
• 6 cups potatoes (peeled and cut into 1/2-inch cubes)

For the topping:

• 1/4 cup butter (melted)
• 1 3/4 cups Panko bread crumbs
• 1/2 teaspoon garlic powder
• 1/4 teaspoon smoked paprika

Method

 

1. Peel and cut potatoes into 1/2-inch cubes, then place in a bowl of cold water to prevent browning. Shred the zucchinis using a box grater or food processor, then wrap them tightly in a clean kitchen towel and squeeze firmly to remove excess moisture—this is crucial for preventing a watery casserole. Preheat your oven to 350°F while you prepare the remaining ingredients.
2. Melt 1/4 cup butter in a large skillet over medium heat, then add the sliced green onions and cook for about 2 minutes until fragrant and slightly softened. Pour in the sour cream and cheese sauce, stirring constantly until the mixture begins to bubble. Add the shredded cheddar cheese and stir until completely melted and smooth—the sauce should be creamy and cohesive at this point.
3. Drain the potatoes from their cold water and pat them dry with paper towels to remove excess moisture. Fold the drained potatoes and squeezed zucchini from Step 1 into the cheese sauce from Step 2, stirring gently but thoroughly until all vegetables are evenly coated. Pour the mixture into a 9x13 inch baking dish, spreading it into an even layer. I like to do a quick taste test of the sauce mixture at this point and add a pinch of salt if needed, since the vegetables will release some liquid as they cook.
4. In a small bowl, combine the melted butter with the Panko bread crumbs, garlic powder, and smoked paprika, mixing until the breadcrumbs are evenly coated and have a slightly damp texture. Sprinkle this mixture evenly over the top of the casserole, pressing it gently so it adheres to the surface—this creates a delicious golden crust as it bakes.
5. Bake in the preheated 350°F oven for 45-50 minutes until the top is golden brown and the edges are bubbling slightly. The casserole will be piping hot, so let it rest for at least 10 minutes before serving—I find this helps the casserole set up and makes it easier to cut into clean portions. You can serve it warm or at room temperature depending on your preference.