Preheat oven to 350. Grease a 9x13 pan.
Prepare a box of pork (or chicken) stuffing mix according to the package directions.
Layer cooked meat, chopped summer squash, frozen broccoli (thawed), and the stuffing in two layers in the baking dish (putting half of the stuffing on top of the casserole).
Mix 1 can cream of mushroom soup with 3/4 cup milk. Pour over top of casserole.
Cover and bake for 40 minutes. Uncover and bake for 10 minutes or until hot and bubbly.