Mushroom Strata

Mushroom strata is the kind of casserole built for a slow morning. Bread, sauteed vegetables, and a loose custard layer overnight, then bake low and slow with a creamy top the next day. It shows up between quiche and souffle on the brunch spectrum: creamier than the former, sturdier than the latter.

The structure depends on letting the assembled dish rest in the fridge at least an hour (overnight is better). That soaking time is what lets the bread drink up the egg-and-milk mixture and turn custardy instead of soggy. Skip the rest and you get wet bread with dry pockets.

Sauteing the mushrooms, onion, celery, and green pepper first drives off excess water so the strata doesn’t weep during baking. Draining the pan after sauteing is key. Any leftover liquid pools at the bottom of the casserole.

Pro Tips

• Use slightly stale bread if you have it. It holds its shape better than fresh and soaks up custard more evenly.
• Let the baked strata rest 5 to 10 minutes before cutting so the layers set and slice cleanly.
• Swap the condensed cream of mushroom for a homemade bechamel with sauteed mushroom bits if you want to skip canned soup.
• Leftovers reheat beautifully at 325°F (165°C) covered with foil.

Variations

• Add diced ham, crumbled bacon, or cooked sausage to the vegetable layer for a heartier brunch main.
• Swap cheddar for Gruyere or Swiss for a nuttier, more complex top.
• Stir fresh thyme or chives into the egg mixture for an herbal backbone.