Breakfast Casserole

Method

1. sear8 min
   medium-high, well-browned crumbles
   sausage broken up and browned past grey — its fat and browned bits go into the dish with it; this is most of the casserole's seasoning, which is why the salt below is modest
2. whisk3 min
   custard fully blended
   eggs + milk + mustard + salt + pepper until no streaks of white remain — the mustard is invisible in the finished dish and unmistakable in its absence; it is the difference between custard and wet egg
3. prep6 min
   layered in a buttered 9x13
   bread + sausage + half the cheese + scallions tossed and spread, custard poured slowly over every corner, pressed down until the top cubes glisten — any cube still dry now will still be dry tomorrow
4. rest480 min
   refrigerated, covered, overnight
   the whole assembly — the bread drinks the custard cube by cube through the night; this rest is why the finished texture is bread pudding instead of eggs with croutons, and why this dish owns holiday mornings: the work happened yesterday
5. bake45 min
   350°F, remaining cheese on at minute 30, center 160°F
   straight from the refrigerator, until puffed at the edges and just set at the center — a knife should come out clean but the middle should still shimmy slightly; the cheese lands late so it melts and browns instead of hardening into a roof
6. rest10 min
   before cutting into squares — the custard finishes setting off-heat, and the first slice out of an unrested casserole always ends as a scoop