Savory Onion Tart for Lovers

Name: Savory Onion Tart for Lovers
Prep time: 20 min
Cook time: 40 min
Total time: 1 h
Yield: 8 servings
Ingredients: 1 pre-made pie crust; 4 large onions, thinly sliced; 3 tablespoons olive oil; 1 teaspoon salt; 1/2 teaspoon black pepper; 2 cups grated Gruyère cheese; 3 large eggs; 1 cup heavy cream; 1 tablespoon fresh thyme, chopped

Highlighted under: Baking & Desserts

I absolutely adore this Savory Onion Tart, not just because it’s delicious but also because it brings a sense of comfort to our gatherings. The combination of caramelized onions, creamy cheese, and a flaky crust makes for a delightful treat that pleases every palate. I love serving this tart warm, allowing the rich flavors to unfold and fill the room with an inviting aroma. Whether it's a cozy dinner with friends or a romantic date night at home, this tart is sure to impress and satisfy everyone at the table.

Created by

Anna

Last updated on 2026-01-17T14:04:28.420Z

Creating this Savory Onion Tart was a delightful experience that brought back fond memories of cooking with my grandmother. We spent hours in the kitchen together, caramelizing onions to perfection. I've found that slow cooking the onions really enhances their sweetness, which is the key to balancing the flavors in this dish. Trust me, taking the time to caramelize makes all the difference!

When I first made this for a gathering, I was amazed at how quickly it disappeared! It's a dish that invites sharing and conversation. I recommend serving it with a light salad to contrast the rich flavors of the tart. Pair it with a crisp white wine for an elevated experience that you won’t forget!

        Why You Will Love This Tart
        Irresistible caramelized onion flavor that warms the heart
Flaky crust that perfectly complements the creamy filling
Elegant enough for special occasions, yet simple to make

      

Understanding the Ingredients

Choosing the right onions is crucial for achieving the perfect caramelization in this Savory Onion Tart. I recommend using yellow or sweet onions, as they develop a richer flavor when cooked slowly. Red onions can be used for a sharper taste, but remember they won’t caramelize as deeply, which could alter the tart's overall sweetness.

The Gruyère cheese plays a vital role in this recipe, providing a nutty flavor and a creamy texture that complements the caramelized onions beautifully. If Gruyère is difficult to find, a good quality Swiss cheese or even a mix of mozzarella and Parmesan can work as substitutes, but make sure they melt well to retain the tart's creamy consistency.

Technique Tips

The key to perfect caramelized onions lies in patience. Cooking them over medium heat allows the natural sugars to develop without burning. Keep stirring every few minutes, and if you find them drying out before they caramelize, add a tiny splash of water to the pan. This deglazes the bits stuck to the bottom and enhances the flavor further.

When mixing the filling, be sure to allow the caramelized onions to cool slightly before incorporating them into the egg and cream mixture. This is important to prevent curdling, ensuring a smooth and cohesive filling. The mixture should be glossy and well combined before pouring it into the crust.

Serving and Storing

This tart can be enjoyed warm right out of the oven, but letting it rest for about 10 minutes enhances its flavor as it settles. If you're preparing it for an event, consider serving it with a fresh green salad for contrast. A drizzle of balsamic glaze over the top can elevate it further, adding a tangy note that balances the richness of the tart.

If you have leftovers, store them in an airtight container in the refrigerator for up to three days. Reheat in a 350°F (175°C) oven for about 15 minutes until warmed through; this preserves the flaky crust better than microwaving, which can make it soggy. For longer storage, freeze the tart after baking, wrapping it tightly in plastic wrap and foil, and it can be kept for up to two months.

Ingredients

For the Tart

1 pre-made pie crust
4 large onions, thinly sliced
3 tablespoons olive oil
1 teaspoon salt
1/2 teaspoon black pepper
2 cups grated Gruyère cheese
3 large eggs
1 cup heavy cream
1 tablespoon fresh thyme, chopped

Instructions

Preparation Steps

Prepare the Onions

In a large skillet, heat olive oil over medium heat. Add the sliced onions, salt, and pepper. Cook slowly, stirring occasionally, until the onions are caramelized, about 25-30 minutes.

Mix Filling

In a bowl, whisk together the eggs and heavy cream. Stir in the grated cheese and fresh thyme. Combine with the caramelized onions after they have slightly cooled.

Assemble the Tart

Preheat your oven to 375°F (190°C). Place the pie crust in a tart pan. Pour the onion and cheese mixture into the crust, spreading it evenly.

Bake

Bake in the preheated oven for 35-40 minutes, or until the filling is set and the top is golden brown.

Serve

Allow the tart to cool slightly before slicing. Serve warm or at room temperature.

Enjoy Your Tart!

Pro Tips

For an extra flavor twist, try adding crumbled goat cheese along with the Gruyère. The tangy taste will elevate this tart even further!

Making It Your Own

Feel free to experiment with the herbs added to the filling! While fresh thyme lends an earthy flavor that pairs beautifully with onions, adding a pinch of nutmeg or a sprinkle of rosemary can give the dish a unique twist. Just remember to keep the quantity balanced to enhance rather than overpower the natural flavors of the onions and cheese.

For a heartier version of this tart, consider adding sautéed vegetables like mushrooms or spinach to the filling. These additions not only bring extra nutrition but also create layers of flavor that make each bite more complex. Just be cautious not to add too much moisture, which could make the tart soggy.

Scaling the Recipe

If you're hosting a larger gathering, this Savory Onion Tart can easily be scaled up. Simply double or triple the filling ingredients, and bake it in a larger tart pan or multiple smaller ones. Just keep an eye on the baking time; larger tarts may require a few extra minutes in the oven to ensure the filling is set and the top is golden brown.

Conversely, if you're cooking for one or two, consider making mini tarts using a muffin tin. Portion the filling into the cups and use pastry rounds or phyllo dough for a quick crust. They’ll bake in about 20-25 minutes, making them perfect for a quick snack or appetizer!

Questions About Recipes

→ Can I use a different cheese?

Absolutely! You can substitute Gruyère with Swiss cheese or any cheese you prefer.

→ How do I store leftovers?

Store any leftovers in the refrigerator for up to 3 days. Reheat in the oven for the best texture.

→ Can I make this tart in advance?

Yes! You can prepare the filling and assembly ahead of time, then bake it just before serving.

→ What can I serve with this tart?

A simple green salad or roasted vegetables work wonderfully as side dishes.