Servings
Font
Back
Zucchini Casserole
5 from 12 votes

Zucchini Casserole

Zucchini Casserole combines sliced, salted zucchini with sautéed onions in a creamy seasoned sauce of butter, flour, milk, spices, and melted grated Gruyere and Gouda cheeses. Topped with a crisp buttered breadcrumb layer, it bakes to a savory, cheesy dish with tender zucchini and a crunchy topping.

Prep Time
20 mins
Cook Time
30 mins
Total Time
50 mins
Servings: 8 servings
Calories: 238 kcal
Course: Side Dish
Cuisine: American, Vegetarian

Ingredients

  • 1 lb zucchini
  • 2 cups onion finely diced
  • 1 tsp olive oil
  • 3 TBSP butter
  • 3 TBSP all-purpose flour
  • ¾ cup milk (warmed via microwave or stovetop)
  • ¼ tsp salt plus extra as needed/desired
  • ¼ tsp black pepper plus extra to taste
  • ¼ tsp garlic powder
  • ⅛ tsp ground nutmeg
  • 4 oz gruyere cheese freshly grated
  • 4 oz gouda cheese freshly grated
Crispy Italian Breadcrumb Topping
  • ½ cup Italian seasoned breadcrumbs (panko or regular)
  • 1 TBSP butter unsalted

Instructions

PREPWORK
    Cup of Yum
  1. Measure out all your ingredients, this will come in handy as the sauce comes together fast!
  2. Discard the ends, then slice each zuchini into 1/4-inch discs. Take care not to slice them too thin or they will get too soft/mushy while cooking. If bite-sized forkfuls are preferred, feel free to cut the rounds in half lenghtwise.
  3. Sprinkle zucchini slices with sea salt and place on an absorbent (clean) dish towel. Allow to sit a minimum of 15 minutes, though 30-40 minutes will help draw out more water. You'll notice water droplets on top of the slices when this happens. Pat dry on both sides using paper towels to remove as much moisture as possible. No one likes soggy squash!
  4. Preheat oven to 375°F
GET COOKING!
  1. Heat a medium pot to medium-high heat with 1 tsp olive oil. Sauté onions, stirring occasionally. Continue cooking until onions are golden brown and tender.
  2. Move onions to the side (if possible) and add 3 TBSP butter. Once melted, add the flour, whisking with a metal whisk constantly for 2 minutes while it bubbles and darkens in color. This roux will thicken the sauce. Pour heated milk into the butter-flour mixture and whisk well. Bring to a light boil, whisking constantly for 1 minute or until the mixture has thickened.
  3. Remove from heat and add salt, pepper, garlic powder, and nutmeg. Working in 2-3 batches, add half the Gruyere cheese and all of the Gouda cheese, whisking in between each batch to gently melt the cheese.
  4. Arrange zucchini in a medium baking dish and top with your sauce. Sprinkle with remaining gruyere cheese. Bake at 375°F for approx. 20-25 minutes, until the top is golden brown and the zucchini has reached ideal tenderness.
  5. While the casserole bakes, add Italian-seasoned breadcrumbs to a heated pan/skillet with butter and gently toast until golden. Carefully sprinkle over casserole once ready and finish remaining bake time.
  6. Enjoy hot!

Notes

  • If you don't have panko or seasoned breadcrumbs, crushed Ritz crackers make a tasty alternative for the topping.
  • Salting sliced zucchini and letting it sit draws out moisture, which should be patted dry before cooking to avoid soggy casserole.
  • Nutrition information provided is estimated; adjust ingredients as preferred for dietary needs.

Nutrition Information

Calories 238kcal (12%) Carbohydrates 14g (5%) Protein 11g (22%) Fat 16g (25%) Saturated Fat 9g (45%) Cholesterol 48mg (16%) Sodium 390mg (16%) Potassium 286mg (6%) Fiber 2g (8%) Sugar 5g (10%) Vitamin A 560IU (11%) Vitamin C 13mg (14%) Calcium 303mg (30%) Iron 1mg (6%)

Nutrition Facts

Serving: 8 servings

Amount Per Serving

Calories 238

% Daily Value*

Calories 238kcal 12%
Carbohydrates 14g 5%
Protein 11g 22%
Fat 16g 25%
Saturated Fat 9g 45%
Cholesterol 48mg 16%
Sodium 390mg 16%
Potassium 286mg 6%
Fiber 2g 8%
Sugar 5g 10%
Vitamin A 560IU 11%
Vitamin C 13mg 14%
Calcium 303mg 30%
Iron 1mg 6%

* Percent Daily Values are based on a 2,000 calorie diet.