Breakfast Casserole problems, diagnosed

Start with the center and the wettest ingredients. A breakfast casserole that is still loose in the middle usually needs more time to set, while a casserole that leaks water around otherwise-set eggs points more toward vegetables that were not drained or cooked dry enough. In bread-based casseroles, also check whether the bread had enough time to absorb the custard and whether the egg-to-liquid ratio was much wetter than the recipe intended.