Pin There's something about the smell of sourdough toasting in butter that makes you forget you're cooking something as simple as eggs. I discovered this frittata on a lazy Sunday morning when I had half a loaf going stale and a farmers market haul of spring vegetables demanding attention. The crust idea came from watching my neighbor casually layer bread into a pan, and I thought, why not? Twenty minutes later, this crispy-bottomed, custardy-centered masterpiece emerged, and suddenly brunch felt like an accomplishment.
I made this for my in-laws during an Easter brunch, and my mother-in-law asked for the recipe before she'd even finished her first bite. That moment—when someone you're trying to impress asks for your secrets—is exactly when you know you've found something worth keeping around. She's made it three times since, which I take as the highest compliment.
Ingredients
- Sourdough bread (6 slices, crusts removed): The crust removal matters because those thick edges won't soften properly and create awkward texture gaps; save the crusts for breadcrumbs instead.
- Unsalted butter (2 tbsp, melted): This is your insurance policy for a golden, crispy bottom layer that won't stick to the pan.
- Asparagus (1 cup, 1-inch pieces): Cut them uniform so they cook evenly; thin spears work best because thick ones can stay woody in the center.
- Cremini or button mushrooms (1 cup, sliced): The earthiness grounds the whole dish and actually helps the eggs taste more savory.
- Shallot (1 small, finely chopped): This is better than onion here because it dissolves into the vegetables instead of announcing itself loudly.
- Olive oil (2 tbsp): Good quality makes a difference since you taste it in the sautéed vegetables.
- Large eggs (8): Room temperature eggs whisk smoother and cook more evenly; pull them from the fridge 10 minutes before you start.
- Whole milk (1/3 cup): The liquid component that makes the frittata creamy rather than rubbery.
- Heavy cream (1/4 cup): This is the difference between decent and velvet; don't skip it.
- Gruyère cheese (1/2 cup, grated): It melts beautifully and adds a subtle nutty depth that Cheddar just can't match.
- Parmesan cheese (1/4 cup, grated): The sharp partner to Gruyère's mellow notes, keeping everything balanced.
- Fresh chives (2 tbsp, chopped): Add these right at the end of whisking so they stay bright and don't turn dark or bitter.
- Salt (1/2 tsp) and black pepper (1/4 tsp): Taste as you go because the cheeses bring saltiness too.
Instructions
- Set your stage:
- Preheat the oven to 375°F and grease your springform pan or pie dish generously. This matters because even well-buttered bread can surprise you with sticking sometimes.
- Build your crust:
- Arrange the sourdough slices to cover the bottom and sides, overlapping slightly like shingles so you don't have gaps. Brush generously with melted butter—lean into it—then bake for 8 to 10 minutes until the edges turn golden and the bread firms up.
- Sauté your vegetables:
- Heat olive oil over medium heat and start with the shallot, letting it soften for about a minute before adding the mushrooms. Once the mushrooms release their moisture and turn golden, add the asparagus and cook everything together for another 2 to 3 minutes until the asparagus brightens slightly but stays crisp-tender.
- Whisk your custard:
- In a large bowl, crack the eggs and whisk them with milk, cream, and cheeses until the mixture looks smooth and unified. This is also when you add the chives, salt, and pepper; take a moment to taste a tiny drop and adjust seasoning if needed.
- Assemble and bake:
- Spread the warm sautéed vegetables over your crispy sourdough crust, then pour the egg mixture over everything slowly so it settles evenly. Bake for 25 to 30 minutes—you'll see the edges puff first, then the center will firm up, and the top will turn a light golden brown.
- Rest and serve:
- Pull it from the oven and let it cool for 5 minutes; this brief rest helps it hold together when you slice it. Serve it warm or even at room temperature, which makes it perfect for make-ahead entertaining.
Pin My youngest decided this was her favorite dinner when she was four, which surprised me because she'd spent months refusing anything with mushrooms. Now she calls it her special egg pie, and watching her fork through that crispy sourdough layer to reach the custardy center is exactly the kind of small victory that makes home cooking feel worthwhile.
Why Spring Vegetables Matter Here
Spring asparagus and mushrooms aren't just trendy—they actually have the right texture profile for this dish. Asparagus stays slightly firm even when cooked, which prevents the frittata from feeling mushy, and mushrooms release just enough moisture to keep everything tender without making it watery. If you're cooking this in winter, cremini mushrooms are your year-round hero because they're consistent and reliable, but don't hesitate to swap in zucchini, bell peppers, or even broccoli if that's what you have on hand.
The Sourdough Crust Secret
Most people think of sourdough as bread for sandwiches, but it's actually perfect here because the flavor holds up against rich eggs and cheese without tasting out of place. The tanginess plays beautifully with Gruyère, and the structure—that open crumb—lets the egg mixture soak in just slightly while still maintaining crispness. If you don't have sourdough, a day-old French baguette or even challah works, though you lose that subtle sour note that makes this special.
Make It Your Own
This frittata is genuinely flexible, which is half its charm. You can load it with whatever vegetables you have lingering in the crisper drawer, add crispy pancetta or smoked salmon if you're not vegetarian, or even layer in cooked spinach and caramelized onions if you're feeling ambitious. The egg-to-dairy ratio stays the same, so the structure holds no matter what you're filling it with.
- Cook any vegetables that need more time before adding quick-cooking ones like asparagus or thinly sliced tomatoes.
- For dairy-free, swap milk and cream for unsweetened oat milk and cheese for a good plant-based option, though the flavor shifts slightly.
- Leftovers keep beautifully in the fridge for three days and reheat gently in a 300°F oven without drying out.
Pin This frittata somehow manages to feel both casual and special, which is exactly the kind of recipe you end up making over and over. Make it once, and you'll understand why it deserves space in your regular rotation.
Recipe Questions
- → How do I prevent the sourdough crust from becoming soggy?
Brush the sourdough slices with melted butter and pre-bake until just crisp before adding the filling. This helps create a barrier that keeps the crust firm and prevents sogginess.
- → Can I use other types of mushrooms besides cremini?
Yes, button mushrooms or any firm, flavorful mushrooms work well. They add depth to the sautéed vegetable mix without overpowering the dish.
- → What is the best way to sauté the vegetables?
Start by cooking the shallots in olive oil until fragrant, then add mushrooms and cook until softened. Finally, add the asparagus for a few minutes to keep it tender-crisp.
- → How can I make this dish suitable for a dairy-free diet?
Substitute the Gruyère and Parmesan with plant-based cheese alternatives and use a plant-based milk substitute in the egg mixture.
- → What serving suggestions complement this dish?
Serve alongside a fresh green salad and a crisp white wine like Sauvignon Blanc to balance the rich, savory flavors.
- → Can this dish be prepared ahead of time?
Yes, you can prepare the crust and sauté the vegetables in advance, assemble, and bake just before serving to maintain freshness.
