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Cheesy Asparagus Casserole

Asparagus Casserole with French Fried Onions

Asparagus Casserole is an easy holiday dish that is creamy inside with crunchy French onion fries toppings. Just the perfect side dish to go on your dinner table for Thanksgiving or Easter!
Course Main Course, Side Dish
Cuisine American
Keyword Asparagus Casserole, French Fried Onions
Prep Time 1 hour
Cook Time 30 minutes
Total Time 1 hour 30 minutes
Servings 8 servings
Calories 516kcal
Author Catalina Castravet


Homemade French Fried Onions (or use store-bought):

  • 3 large onions sliced into thin rings
  • 1 1/2 cups milk
  • 1 1/2 cups all-purpose flour
  • 1 teaspoon garlic powder
  • 1/4 teaspoon salt
  • 1/4 teaspoon ground black pepper
  • Vegetable or canola oil for frying

Asparagus Casserole:

  • 4 tablespoons unsalted butter
  • 2 pounds fresh asparagus trimmed and cut into 1-inch pieces
  • 8 ounce package white mushrooms sliced
  • 1 small onion thinly sliced
  • 1/4 cup all-purpose flour
  • 1 1/2 cups light cream
  • 1/2 cup mayo
  • 1/2 cup cream cheese softened to room temperature
  • 1/2 cup cheddar cheese shredded
  • 1/2 cup Swiss cheese shredded
  • 1/2 teaspoon thyme
  • 1 teaspoon lemon zest
  • 1/4 teaspoon paprika
  • 1/2 teaspoon salt
  • 1/4 teaspoon pepper


Homemade French Fried Onions (or use store-bought):

  • Slice the onions into thin rings and separate them into individual rings, add them to a large bowl.
  • Add milk to the onion rings and let soak for 20 minutes.
  • In a medium bowl combine flour, salt, garlic powder, and ground black pepper. Whisk to combine.
  • When ready to cook, add oil to a large, deep skillet over high heat (or deep fryer).
  • Once the oil is hot, working in batches, add a handful of onion rings to the flour mixture, cover well and shake any excess. Transfer to the hot oil and fry until golden brown, turning often.
  • Remove the French fried onions and place them on a baking sheet that has been covered with paper towels to drain excess oil.
  • Repeat with the remaining onion rings.

Asparagus Casserole:

  • First, grease a 9x13 inch casserole dish and preheat the oven to 350 degrees.
  • Place a large non-stick pan over medium heat and add butter and melt, add onion slices and cook for 1-2 minutes, until just tender.
  • Add minced garlic, asparagus, mushrooms, and cook, stirring occasionally, for about 6-8 minutes.
  • Season with salt, pepper, paprika, thyme, and lemon zest. Stir to combine.
  • In a measuring cup combine cream and flour, whisk to combine.
  • Add the flour mixture to the skillet and cook, stirring for 3-4 minutes, or until thickened.
  • Reduce heat to low and mix in mayonnaise and cream cheese, stir until fully combined.
  • Remove from heat and stir in both kinds of cheese until melted.
  • Crush about 1 1/2 cups of french-fried onions and mix them into the asparagus mixture.
  • Transfer mixture to a prepared casserole dish.
  • Sprinkle remaining french-fried onions on top.
  • Place in oven and bake for 30-40 minutes or until mixture is bubbly.
  • Top with more french-fried onions and serve.


Calories: 516kcal | Carbohydrates: 35g | Protein: 13g | Fat: 37g | Saturated Fat: 17g | Cholesterol: 91mg | Sodium: 525mg | Potassium: 620mg | Fiber: 5g | Sugar: 8g | Vitamin A: 1805IU | Vitamin C: 11.8mg | Calcium: 263mg | Iron: 4.6mg