In a large mixing bowl, combine asparagus, peas, and shredded cheddar cheese.
In a saucepan, melt butter over medium heat. Stir in flour and cook for 1-2 minutes. Gradually whisk in milk, cooking until the mixture thickens. Season with salt and pepper.
Pour the sauce over the asparagus and pea mixture, stirring to combine.
Transfer the mixture to a baking dish and bake for 30 minutes, or until the top is golden and bubbly.
Let it cool for a few minutes before serving.
Notes:
This casserole is a great way to use up fresh asparagus and makes for a comforting meal.