This quiche uses roasted summer squash and leeks instead of raw vegetables, which keeps the custard from turning watery and gives the filling real flavor. It takes about two hours start to finish, but most of that is hands-off oven time — and you can split the work across two days. If you’ve never made quiche before, this is a good one to start with.
The short version of why this works
Two things make this quiche work. First, roasting the squash and leeks at 425°F before they go into the crust drives off most of their water. Summer squash is about 95% water — skip that roasting step and it releases all of that liquid into your custard as it bakes, leaving you with a soggy bottom and a filling that never quite sets. Second, blind-baking the crust before adding any filling gives the pastry a head start on cooking so it doesn’t go soft under the weight of the eggs and cheese. Both steps add time, but neither one is difficult, and both are doing real work.
Smart swaps
- Summer squash: Yellow crookneck and zucchini both work well here. Avoid very large squash — anything over about 14 oz tends to have more seeds and more water. Stick to medium-sized ones.
- Leeks: One stalk is a modest amount. If you can’t find leeks, two or three thinly sliced shallots roasted the same way are a reasonable substitute. A small yellow onion works too, though the flavor is sharper.
- Cheddar: Sharp cheddar is worth seeking out here — mild cheddar doesn’t contribute much. If you only have mild on hand, add an extra tablespoon of Parmesan to compensate.
- Fresh thyme: Dried thyme works in a pinch. Use about one teaspoon dried in place of one tablespoon fresh. Skip the garnish of extra thyme sprigs on top — not worth the extra dish.
- Milk: Whole milk gives the best texture. Lower-fat milk produces a slightly less rich custard that still sets properly.
Common problems and fixes
- The crust shrinks down the sides during blind-baking: This usually means the dough wasn’t pressed firmly enough into the corners of the pie plate, or it wasn’t chilled before going into the oven. Press it snugly into the edges, then refrigerate the lined crust for 15 minutes before blind-baking.
- The custard is still liquid in the middle after the stated bake time: Ovens vary. If the edges are set but the center is still sloshy (not just a gentle wobble), tent the quiche loosely with foil to prevent the crust from over-browning and give it another 10 minutes. Check again with a knife.
- The filling puffs up and cracks on top: This happens when the oven is too hot or the quiche bakes too fast. An oven thermometer is the easiest way to catch this — many home ovens run 25°F hotter than the dial says. A few surface cracks don’t affect the flavor or texture once sliced.
- Slices fall apart when you cut them: The custard needs time to firm up after it comes out of the oven. Cutting too soon — before that 15–20 minute rest — is almost always the reason. Let it sit on the rack until it’s just warm, not hot.
- The vegetables slide around when you pour in the custard: Pour slowly from the side of the dish, not directly onto the vegetables. A ladle gives you more control than pouring straight from the bowl.
Leftovers and make-ahead
Leftover quiche keeps well in the fridge for up to four days, covered tightly. To reheat individual slices, a 325°F oven for about 15 minutes gives you a better result than the microwave, which tends to make the custard rubbery. If you want to freeze it, let the quiche cool completely first, then wrap individual slices in plastic wrap and foil — they’ll keep for up to two months. Thaw overnight in the fridge before reheating. For the make-ahead approach, the roasted vegetables and the blind-baked crust can both be prepared the evening before; store the vegetables in a covered container in the fridge and leave the crust at room temperature, loosely covered. The next morning, all you’re doing is whisking the custard and assembling.
Roasted Summer Squash Quiche with Leeks and Thyme
Ingredients
- 1 9-inch pie crust store-bought or homemade, rolled out
- 1 large summer squash such as yellow crookneck or zucchini (about 12 oz), cut in half lengthwise and thinly sliced
- 1 stalk leek white and light green parts, thinly sliced and rinsed well
- 2 tablespoons olive oil
- 1 pinch sea salt
- 6 medium eggs
- 1 cup milk
- 6 ounces cheddar cheese shredded
- ½ cup parmesan cheese finely grated
- 1 tablespoon fresh thyme leaves about 4–5 sprigs, stripped
- ½ teaspoon salt
Instructions
- (This step can be done the evening before.) Preheat oven to 425°F / 220°C (200°C fan-forced). Spread squash and leek slices on a parchment-lined rimmed baking sheet in a single layer. Drizzle with olive oil and sprinkle generously with sea salt. Toss to coat evenly. Roast for 30 to 35 minutes, tossing halfway through, until the vegetables are tender and just starting to brown at the edges. Set aside to cool.
- Reduce oven temperature to 375°F / 190°C (170°C fan-forced). Fit the rolled-out pie dough into a 9-inch pie plate, pressing it gently into the edges. Prick the base several times with a fork. Line the crust with parchment paper and fill with pie weights or dried beans. Blind-bake for 12–15 minutes until the edges are just set and lightly golden. Remove the weights and parchment and bake for a further 3–5 minutes until the base looks dry. Remove from the oven and allow to cool for 5 minutes.
- Scatter the cooled roasted squash and leeks evenly across the bottom of the blind-baked crust. In a large bowl, whisk together the eggs and milk until smooth. Stir in the cheddar, Parmesan, thyme leaves, and salt. Pour the custard mixture over the vegetables — it should come close to the top of the crust but not overflow. Bake at 375°F / 190°C (170°C fan-forced) for 50 to 60 minutes, until the custard is set around the edges but still has a very slight wobble in the centre. A knife inserted 1 inch from the centre should come out clean.
- Remove the quiche from the oven and let it cool on a wire rack for at least 15–20 minutes before slicing. This allows the custard to firm up so slices hold their shape.
Nutrition
Your questions, answered
Can I use a store-bought pie crust?
Yes, a store-bought refrigerated pie crust works fine here. Just make sure it’s fully thawed and pliable before you press it into the pie plate — a cold, stiff crust cracks when you try to fit it into the dish.
How do I know when the quiche is actually done?
The custard should be set around the edges with just a slight wobble in the very center — similar to how a just-set Jell-O moves. A knife inserted about an inch from the center should come out clean; if it comes out wet and eggy, give it more time.
Do I really need pie weights, or can I skip them?
You need something to weigh the crust down during blind-baking. Without weights, the base puffs up and you end up with a shallow, uneven shell that won’t hold the filling properly. Dried beans, dry rice, or even dry lentils all work just as well as proper pie weights.
My leeks always seem gritty. How do I clean them properly?
Slice the leeks first, then put them in a bowl of cold water and swish them around — the grit sinks to the bottom. Lift the slices out with your hands or a slotted spoon rather than pouring them through a strainer, which just dumps the grit back over them.
Can I make this without meat — is it filling enough as a main dish?
It’s completely vegetarian as written, and with six eggs and two cheeses it’s genuinely filling. A simple green salad on the side is enough to make it a full meal for most people.
What to cook next
- Fluffy buttermilk pancakes for your next weekend brunch
- Gourmet avocado toast with poached egg
- Sparkling mimosa to serve alongside brunch
- Caramelized Brussels sprouts with balsamic glaze
