Preheat oven to 350°F and grease a 9x13 baking dish.

Trim the ends of the asparagus and chop into bite-sized pieces. Set aside.

In a large pot or Dutch oven, melt butter over medium heat. Add the asparagus, mushrooms, and onion. Cook for 5 minutes, stirring occasionally.

Add flour to the vegetable mixture and cook for 1 minute, stirring constantly.

Slowly pour in the milk and continue cooking until mixture thickens.

Remove from heat and mix in mayo, sour cream, shredded cheese, salt, pepper, paprika, and ½ cup of the fried onions.

Transfer the mixture to the prepared baking dish and spread evenly.

Top with remaining fried onions.

Bake for 33-35 minutes or until golden brown on top. Serve warm.