Breakfast Casserole

Steps

1. Sear8 min
   medium-high, well-browned crumbles
   • breakfast sausage
   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
   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
   • scallions
   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