Heat oven to 400°. Heat asparagus, ham, milk, soup and 3/4 cup of the cheese to boiling in 3-quart saucepan, stirring constantly. Boil and stir 1 minute. Spread in ungreased 2-quart casserole. Stir biscuit mix, milk and remaining 1/4 cup cheese in small bowl until blended. Pour evenly over ham mixture. Bake uncovered about 30 minutes or until golden brown and toothpick inserted in biscuit layer comes out clean.