The sauce binds the casserole. It holds the filling together, carries the flavour into the starch, and keeps the bake from drying out. The 1950s casserole got its sauce from a can of condensed soup; the from-scratch version is a gravy, a curry, a tomato sauce, or a cheese sauce, which is what the canned soup was standing in for.
The variables
- Amount. Enough to coat everything with some to spare. The starch drinks sauce in the oven, and rice and pasta drink the most.
- Thickness. A little looser than you’d serve it. It thickens as the starch soaks it up and as it bakes. A flour-thickened gravy or a rouxRouxEqual weights of fat and flour cooked together to thicken a sauce.-based sauce holds up best.
- Match. Turkey gets turkey gravy, beef gets beef gravy, takeout keeps its own sauces. A mismatched sauce tastes like two dinners.
Options
| Option | Pick it when | Changes |
|---|---|---|
| Gravy (Simple chicken, pork, and beef gravy) | It’s a pie with mash on top | Nothing: the classic |
| The takeout’s own sauces | It’s takeout leftovers | The starch: rice or noodles underneath to catch them |
| Tomato sauce or meat sauce | It’s a baked pasta | The top: cheese |
| Cheese sauce (mornay) | It’s mac and cheese | The bake: stop at bubbling, or it breaks |
How it fails
- Dry: not enough sauce for the starch. Leftover rice and pasta are the thirstiest.
- Soupy: the sauce was thin and the vegetables let out water. Thicken it before it goes in.
- Grainy cheese sauce: baked too hot or too long.