Crustless Zucchini Tomato Quiche

This low-carb crustless quiche combines fresh zucchini and juicy tomatoes for a light, savory meal. It is a versatile dish that works perfectly for a healthy breakfast, a weekend brunch, or a simple dinner.

List of ingredients

• 1 tablespoon olive oil – used for sautéing the base vegetables.
• 1 small onion, finely chopped – adds a sweet, aromatic base.
• 2 medium zucchinis (about 3 cups), thinly sliced – the primary vegetable component.
• 2 medium tomatoes, seeded and diced – provides acidity and moisture.
• 3 large eggs – binds the ingredients and creates the custard.
• 1 cup milk (whole or 2%) – adds creaminess to the filling.
• ½ cup heavy cream – enhances the rich texture (can be replaced with more milk).
• 1 cup shredded mozzarella cheese – provides a mild, melty quality.
• ½ cup grated Parmesan cheese – adds a sharp, salty depth.
• 2 cloves garlic, minced – introduces a pungent, savory flavor.
• 1 teaspoon dried basil (or 1 tablespoon fresh basil, chopped) – adds a classic herbal note.
• ½ teaspoon dried oregano – adds an earthy, Mediterranean aroma.
• ½ teaspoon salt – enhances all the flavors in the dish.
• ¼ teaspoon black pepper – provides a subtle, warm spice.
• Pinch of red pepper flakes (optional) – adds a hint of heat.

step-by-step instructions

1. Preheat Oven: Set your oven to 375°F (190°C). Grease a 9-inch pie dish or quiche pan with cooking spray or butter to prevent sticking.
2. Cook Vegetables: Heat olive oil over medium heat in a large skillet. Add the finely chopped onion and cook for about 3 minutes until it becomes softened. Stir in the thinly sliced zucchini and minced garlic, cooking for another 5–6 minutes until the zucchini is tender. Remove the pan from the heat and let the mixture cool slightly.
3. Whisk Egg Mixture: In a mixing bowl, combine the eggs, milk, heavy cream, dried basil, dried oregano, salt, black pepper, and optional red pepper flakes. Whisk until the mixture is smooth and well combined.
4. Assemble Quiche: Spread the sautéed zucchini and onion mixture evenly across the bottom of the prepared dish. Place the diced tomatoes on top of the zucchini. Sprinkle the shredded mozzarella and grated Parmesan evenly over the vegetables. Carefully pour the whisked egg mixture over the entire assembly.
5. Bake: Place the dish in the center of the oven and bake for 35–40 minutes. The quiche is done when the center is set and the top has turned a light golden brown.
6. Cool and Serve: Remove from the oven and allow the quiche to rest for 10 minutes. This resting period allows the proteins to set, making it easier to slice. Serve warm or at room temperature.

Professional Texture Tips

Remove Excess Moisture from Zucchini

Zucchini has a high water content that can release during baking, potentially making the quiche soggy. To prevent this, you can toss the sliced zucchini with a pinch of salt and let it sit for 10 minutes before sautéing. Use a clean kitchen towel or paper towels to squeeze out as much liquid as possible before adding them to the skillet.

Seed the Tomatoes Carefully

The center of the tomato contains seeds and a gelatinous liquid that can seep into the egg custard. Using a spoon to scoop out the seeds and pulp before dicing ensures that only the firm outer walls of the tomato are used. This keeps the quiche structure firm and prevents watery pockets from forming around the tomato pieces.

Use Room Temperature Eggs and Dairy

Bringing your eggs, milk, and cream to room temperature before whisking helps create a more stable emulsion. This results in a smoother, more consistent custard that rises evenly in the oven. If you are in a rush, place the eggs in a bowl of warm water for a few minutes to take the chill off.

Alternative Ingredient Options

Substituting Mozzarella for Other Cheeses

While mozzarella provides a classic melt, you can use feta for a saltier, tangier profile. Swiss or Gruyère are excellent choices if you prefer a nuttier flavor that complements the zucchini. If using a very salty cheese like feta, reduce the added salt in the egg mixture to maintain balance.

Using Different Milk Options

For a lighter version of this recipe, you can omit the heavy cream and use 1.5 cups of whole milk or 2% milk. For a dairy-free alternative, unsweetened almond or soy milk works well. If using plant-based milk, ensure it is not sweetened to avoid an odd flavor profile in the savory custard.

Fresh Versus Dried Herbs

Dried herbs are concentrated and provide a steady flavor throughout the bake. If you prefer fresh basil or parsley, use a ratio of three to one compared to the dried measurement. Stir fresh herbs into the egg mixture at the very end to preserve their bright color and delicate aroma.

Customizing Your Quiche

Adding Leafy Greens

Fresh spinach or kale can be added to increase the nutritional value of the dish. Sauté the greens briefly with the onions and garlic until wilted, then squeeze out any excess moisture. Mix them directly into the zucchini layer before adding the eggs.

Incorporating Savory Mushrooms

Sliced cremini or button mushrooms add a rich, umami depth to the quiche. Sauté them in the olive oil until they have browned and released their moisture. Adding mushrooms transforms this from a light brunch item into a more substantial dinner option.

Adding Plant-Based Proteins

To make the dish heartier, you can stir in diced smoked tofu or plant-based sausage crumbles. Ensure these proteins are pre-cooked and browned in the skillet before adding them to the assembly. This adds a chewy texture and a savory, smoky flavor that pairs well with the cheese.

Storage and Preservation

Refrigeration Guidelines

Store leftover slices in an airtight container or wrap the whole quiche tightly in foil. It will remain fresh in the refrigerator for up to 4 days. Keep it on a middle shelf where the temperature is consistent to avoid premature spoilage.

Freezing and Thawing Methods

This crustless quiche freezes remarkably well for long-term meal prep. Allow the quiche to cool completely, then wrap individual slices in plastic wrap and place them in a freezer-safe bag. Store for up to 2 months, and thaw overnight in the refrigerator before reheating.

Reheating Instructions

Oven Reheating for Best Texture

To maintain the best texture, reheat slices in the oven at 350°F (175°C) for about 10–15 minutes. This method prevents the eggs from becoming rubbery and helps the cheese regain its melt. Place the slices on a baking sheet and cover loosely with foil to prevent over-browning.

Microwave Quick Warm-up

For a faster option, microwave individual slices on medium power for 60–90 seconds. To avoid a rubbery consistency, place a damp paper towel over the slice to trap steam. This keeps the interior moist while heating the quiche through.

Common Troubleshooting

Preventing a Watery Quiche

If your quiche turns out too watery, it is usually due to undercooked vegetables or unseeded tomatoes. Ensure the zucchini is sautéed until tender and that the tomatoes are well-drained. Using a higher ratio of cheese can also help absorb some of the excess moisture.

Avoiding a Cracked Surface

Cracks on the top of the quiche often occur when the eggs are over-beaten or the oven temperature is too high. Whisk the eggs until combined but avoid incorporating too much air. If the top browns too quickly while the center is still liquid, cover the dish with foil and lower the oven temperature by 25°F.

Ensuring the Center is Fully Set

The center of a crustless quiche can be tricky to judge. Use a knife or toothpick to poke the middle; it should come out clean without any liquid egg clinging to it. If the edges are golden but the center wobbles, give it another 5 minutes of baking time.

Frequently Asked Questions

Can this be made in a muffin tin?

Yes, you can divide the mixture into greased muffin tins to create individual mini quiches. Reduce the baking time to 20–25 minutes and check for doneness frequently. These are ideal for portion control or serving as appetizers at a party.

Is this dish gluten-free?

Since this recipe is crustless, it is naturally gluten-free. Ensure that your chosen cheeses and any plant-based additives are certified gluten-free if you have a severe sensitivity. This makes it an excellent option for guests with gluten restrictions.

Can I use a cast iron skillet?

A cast iron skillet is an excellent choice for this recipe. You can sauté the vegetables directly in the skillet and then pour the egg mixture on top. Simply transfer the entire skillet to the oven, which provides a more rustic look and an even heat distribution.

Can I use frozen zucchini?

Frozen zucchini can be used, but it must be thawed and squeezed very thoroughly. Frozen vegetables release significantly more water than fresh ones, which increases the risk of a soggy quiche. Sautéing them on high heat helps evaporate the excess liquid more quickly.

What is the best way to slice the quiche?

To get clean, professional-looking slices, use a sharp serrated knife. Let the quiche cool for at least 10 minutes to allow the custard to firm up. Wipe the knife with a damp cloth between slices to remove any residue and ensure a smooth cut.

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