Add milk to biscuit mix all at once; mix and knead according to package directions.
Roll in rectangle 1/2 inch thick.
Sprinkle with cheese and pimiento; roll as for jelly roll.
Cut in 1-inch slices.
Place 5 or 6 biscuits, cut side down, atop hot casserole mixture; brush tops with melted butter; bake.
(Bake remaining biscuits on greased baking sheet.)