The starch is what makes a casserole a meal, and what makes a little filling go a long way. Where it goes matters more than which one it is. On top it’s a lid that browns and keeps the filling moist. Underneath it’s a bed that soaks up the sauce. Mixed through, every bite has some of everything.
The variables
- Position. Top, bottom, or through. Mash and stuffing go on top; rice and noodles go underneath; pasta goes through.
- Doneness. Starch keeps cooking in the oven and drinks the sauce. Cooked pasta should go in a minute or two short of al denteAl denteCooked until tender but still firm at the centre, with a little bite: Italian for “to the tooth”.. Leftover rice and noodles are already done, so they need extra sauce rather than more time.
- Amount. About as much starch as filling, by volume. Less and it’s a stew with a crust; more and it’s dry.
- Pasta size. Small shapes (macaroni, penne) or cut-up long pasta, so it mixes with the sauce. Sheets get layered, and that’s lasagne.
- Dryness. Mash for a topping should be stiff enough to hold a fork’s ridges. Wet mash slumps into the filling and won’t brown.
Options
| Option | Pick it when | Changes |
|---|---|---|
| Mashed potatoes, on top | The filling is in gravy (a pie) | The top: ridged with a fork, browned under the broiler |
| Stuffing, on top or as a middle layer | It’s holiday leftovers | The top: crisps on its own, needs no cheese |
| Rice or noodles, underneath | It’s takeout or curry leftovers | The sauce: add extra, the starch soaks it up |
| Pasta, mixed through | You want a baked pasta | The sauce: loose, since pasta drinks it; cheese on top |
| Tortillas, layered | It’s an enchilada casserole | The sauce: on every layer, so the tortillas soften |
How it fails
- Dry and stodgy: too much starch, or leftover rice with no extra sauce.
- A soggy lid: the mash was too wet, or it went on a filling that was too thin.