Caramelized Onion Goats Cheese

There's something magical about watching onions transform in a hot pan—what starts as sharp and pungent becomes silky and sweet over time. I discovered this tart on a quiet Sunday afternoon when I had a surplus of onions from the farmer's market and wanted to do them justice. The combination of caramelized onions with tangy goats cheese felt like a conversation between two completely different flavors that somehow made perfect sense together. Now it's become my go-to dish whenever I want something elegant but genuinely relaxed.

I made this for a dinner party where everyone expected something complicated, and their faces when they realized how simple it was felt like a small victory. One guest asked for the recipe before dessert even arrived, which tells you everything you need to know.

Ingredients

• Ready-rolled shortcrust pastry (1 sheet, about 250 g): Using store-bought saves time without sacrificing quality—just make sure it's thawed if frozen.
• Olive oil (2 tablespoons): This carries the flavor of the onions, so use something you actually like the taste of.
• Unsalted butter (2 tablespoons): Butter adds richness and helps caramelize the onions faster than oil alone.
• Yellow onions (4 large, thinly sliced): Yellow onions are sweeter than white ones, which is exactly what you want here.
• Sugar (1 teaspoon): Just a pinch to speed up the caramelization and deepen the color.
• Salt and pepper (½ teaspoon each): Season generously—caramelized onions can absorb more salt than you'd expect.
• Fresh thyme (2 teaspoons fresh or 1 teaspoon dried): Thyme's earthiness complements the sweetness of the onions perfectly.
• Soft goats cheese (150 g, crumbled): The tanginess cuts through the richness and prevents the tart from feeling heavy.
• Eggs (3 large): These create the custard base that binds everything together.
• Double cream (200 ml): Don't skip this—it makes the filling luxurious and prevents it from curdling.
• Whole milk (100 ml): Milk balances the richness of the cream and helps the filling set properly.
• Ground nutmeg (¼ teaspoon): A whisper of nutmeg adds warmth without announcing itself.

Instructions

Get your oven ready and prepare the pastry:

Preheat to 190°C (375°F) and let the pastry rest in the tart tin for 10 minutes in the fridge—this prevents shrinking during baking. Prick the base gently with a fork to help it cook evenly.

Blind bake for a crisp shell:

Line the pastry with parchment and fill with baking beans, then bake for 15 minutes. Remove the beans and parchment, and bake 5 more minutes until pale golden and firm to the touch.

Coax the onions into sweetness:

While the pastry bakes, heat oil and butter in a large skillet over medium-low heat and add your sliced onions with the sugar, salt, and pepper. Stir occasionally—this is a gentle process, not a race—for 20–25 minutes until they're soft, translucent, and golden brown. Add the thyme and cook 2 minutes more, then let them cool slightly before using.

Build the custard filling:

Whisk together eggs, cream, milk, nutmeg, salt, and pepper in a bowl until smooth and well combined. This custard is what transforms the tart from just cheese and pastry into something truly special.

Layer and fill:

Spread the cooled caramelized onions over the blind-baked pastry base, scatter the crumbled goats cheese on top, and slowly pour the egg mixture over everything. Pour gently so the filling settles evenly without splashing.

Bake until golden and just set:

Bake for 25–30 minutes until the filling is set but still has a slight jiggle in the center—it will continue cooking as it cools. The top should be pale golden and smell absolutely irresistible.

Cool and serve:

Let the tart rest for 10 minutes before slicing, which makes it much easier to serve neatly. It's equally delicious warm or at room temperature.

Save

The first time someone bit into a slice and closed their eyes, I realized this wasn't just a tart—it was the kind of dish that makes people pause mid-conversation. That moment is why I keep making it.

Timing Tips

You can caramelize the onions up to two days ahead and store them in the fridge, which means you're really only 40 minutes away from a finished tart on any given day. The pastry blind bakes while the onions cook, so these two steps overlap beautifully if you plan right. If you're making this for guests, do the onions the day before and focus on assembly and baking when people arrive.

Flavor Variations

I've swapped goats cheese for crumbled feta when I wanted something sharper, and it shifts the entire personality of the tart in the best way. A handful of toasted walnuts scattered over before baking adds a woody crunch that nobody expects but everyone loves. The earthy notes of walnuts play so well with the sweetness of the onions that it feels like a revelation.

Making It Your Own

This tart is a starting point, not a rigid formula—I've added sautéed mushrooms, crispy bacon bits, and even a thin layer of mustard spread on the pastry before filling it. Each addition teaches you something new about how flavors combine. The beauty is in knowing the foundation is solid enough to experiment on.

• Try spreading a thin layer of whole-grain mustard on the blind-baked pastry for a subtle flavor boost.
• Add a small handful of crispy pancetta or prosciutto pieces between the onions and cheese for a salty contrast.
• Serve with a crisp green salad dressed in a bright vinaigrette to balance the richness of the custard.

Save

This tart has taught me that good food often comes from slowing down and paying attention to small transformations in the pan. It's the kind of recipe that tastes like effort but feels effortless to make.

Recipe FAQs

→ How do I caramelize onions properly?

Cook sliced onions slowly over low to medium heat with oil and butter, stirring often until they turn golden and soft, usually 20-25 minutes.

→ Can I prepare the tart crust in advance?

Yes, blind bake the pastry crust ahead of time, then cool it before adding the filling to maintain a crisp base.

→ What can I substitute for goats cheese?

Feta or blue cheese offer similar tang and creaminess if you prefer a different flavor profile.

→ How to ensure the filling sets well?

Use a mixture of eggs, cream, and milk, and bake until the filling is golden and firm to touch, about 25-30 minutes.

→ Are there garnish options to enhance flavor?

Fresh thyme sprigs and arugula work well to add herbal notes and fresh texture before serving.

→ Can I add nuts for texture?

Sprinkle toasted walnuts over the filling before baking to add crunch and nutty flavor.