Indian Summer Squash Quiche

This squash quiche makes the most of late-summer yellow squash when it’s abundant and cheap. Tender slices layered over sauteed onions and Swiss cheese in a pie shell, then baked in a light buttermilk custard with oregano until golden and set.

The custard uses a clever shortcut: powdered buttermilk mixed with water instead of liquid buttermilk. This gives you the tang and richness without needing a full carton. Two whole eggs plus two extra yolks make the custard richer and more golden than an all-whole-egg version.

Drain the steamed squash thoroughly on paper towels before assembling. This step is critical. Summer squash is mostly water, and any excess moisture will make the custard weep and the crust soggy. Press the slices gently to remove as much liquid as possible.

The layering order matters: onions on the bottom, squash arranged on top, cheese over everything, then the custard poured in. This keeps the squash visible through the top of the set custard instead of buried in the bottom.

Kitchen Tips

• Steam the squash until just barely tender. It cooks more in the oven, so overdone squash will turn mushy.
• Drain squash on paper towels and blot dry. Wet squash is the number one reason quiches turn watery.
• Cover the crust edges with foil strips if they brown too fast during baking.
• Let the quiche rest 10 minutes after baking for cleaner slices.

Variations

• Swap squash for lightly cooked broccoli, asparagus, or cauliflower depending on what’s in season.
• Use fresh herbs instead of dried. Increase to ¾ teaspoon for basil, thyme, or tarragon.
• Cut into thin wedges for an appetizer, or larger wedges for a main dish.