01 -
Place the asparagus, mayonnaise, and grated cheddar cheese in a large bowl.
02 -
In a skillet over medium heat, add the diced onion with a drizzle of oil. Sauté for about 5 minutes until soft and slightly browned. Add the minced garlic and sprinkle the flour over the onion mixture. Stir to form a roux and cook for 1-2 minutes.
03 -
Slowly pour the milk into the skillet while stirring to incorporate it into the flour mixture. Let the sauce bubble and thicken slightly. Season with salt and pepper to taste.
04 -
Pour the milk sauce into the bowl with the asparagus, mayonnaise, and cheese. Stir thoroughly to combine the ingredients.
05 -
Transfer the mixture into a 9x13-inch baking dish. Sprinkle the crushed Ritz crackers evenly over the top. Bake at 375°F (190°C) for 40-50 minutes, or until the asparagus is tender and the cheese is bubbly. Broil the top for 1 minute if desired to brown the crackers.
06 -
Let the casserole rest for a few minutes before serving. Enjoy!