If someone on your block has a backyard vegetable patch, chances are you’ve come home to find a bag of zucchini and summer squash with a friendly note on your porch. These prolific Southern garden staples combine with another fundamental element of good neighbordom—the make-and-take casserole—in this classic recipe. Slicing the squash into half-inch-thick rounds, then parboiling, draining, and lightly pressing with paper towels helps absorb excess moisture, so the pieces hold their shape and texture while baking. It’s a little extra effort that pays off—no slippery, slimy squash here. The slices are suspended in a custardy, eggy mixture that rises as it bakes, almost crossing into soufflé territory.