Let’s talk onion tarts. If you’ve never had one, let me tell you… they’re like the fancy cousin of pizza and the comfort food your soul didn’t know it needed.

This onion tart is hands down one of my go-to recipes when I want something a little special but still totally doable. It’s perfect as a party appetizer, Mother's Day, Easter brunch, happy hour with friends, or honestly just for dinner with a side salad when you’re craving something warm and savory.

It has a golden, flaky crust (yes, homemade, but don’t panic, I promise it’s easy), sweet caramelized onions, creamy eggs, and gooey, melty cheese. Oh, and did I mention nutmeg? Just a pinch. Trust me.

Why You’ll Love This Onion Tart

• Simple but fancy. It looks impressive but takes less than 30 minutes to prep.
• Make-ahead friendly. You can caramelize the onions the day before.
• Versatile. Serve it warm, at room temp, or even cold the next day, yes, I’ve eaten it straight from the fridge at 7 a.m. and I have no regrets.

Onion Tart Recipe

Prep Time: 30 minutes
Cook Time: 50 minutes (includes blind baking the crust)
Total Time: 1 hour 20 minutes
Servings: 6–8 slices (or fewer if you're anything like my family and go back for seconds…)

Ingredients

For the crust (shortcrust pastry):

• 200 g all-purpose flour
• 100 g cold unsalted butter, cut into cubes
• 1 egg
• A pinch of salt
• 1–2 tbsp cold water

For the filling:

• 3–4 large onions (about 500 g)
• 30 g unsalted butter
• 100 ml heavy cream (20–30%)
• 2 eggs
• 100 g grated hard cheese (Gruyère, Parmesan, or Cheddar all work beautifully)
• Salt and pepper to taste
• A pinch of nutmeg (optional, but it adds a little magic)

Instructions

1. Make the crust (don’t skip it, it’s worth it!):

Okay, I know homemade crust can sound intimidating, but hear me out. This is a simple shortcrust pastry, and once you try it, you might never go back to store-bought again.

1. In a big bowl, mix the flour and salt. Add the cold butter cubes. Now, using your fingers (or a pastry cutter if you’re fancy), rub the butter into the flour until it looks like fine breadcrumbs. It’s oddly satisfying.
2. Add in the egg and a tablespoon or two of cold water. Gently knead the dough just until it comes together, don’t overwork it.
3. Shape it into a ball, wrap it in cling film, and pop it in the fridge to chill for 30 minutes. (Perfect time to drink something fun and preheat the oven!)

2. Cook those onions (the star of the show):

1. Peel and thinly slice your onions into half-rings. Don’t rush this part, it’s all about the flavor.
2. Melt the butter in a skillet over medium heat and toss those onions in. Cook them slowly for about 20 minutes, stirring often. You want them soft, golden, and sweet, not burnt! Caramelized onions are a labor of love, but sooo worth it.

3. Mix the filling:

1. In a mixing bowl, whisk together the eggs and cream.
2. Add in your grated cheese, a little salt and pepper, and that optional pinch of nutmeg.
3. Give it a stir, and try not to eat it with a spoon (I’ve been tempted).

4. Assemble the tart:

1. Roll out your chilled dough on a floured surface and carefully place it into a tart pan (about 23 cm or 9 inches). Press the dough into the corners and up the sides. Prick the bottom with a fork, this keeps it from puffing up too much.
2. Blind bake it! That’s just a fancy way of saying: cover the crust with parchment paper, fill it with pie weights or dried beans, and bake at 180°C (350°F) for 10 minutes. This helps the crust stay crisp.
3. Take it out, remove the paper and weights, and get ready to fill!

5. Fill and bake:

1. Spread your dreamy, golden onions all over the crust.
2. Pour the creamy, cheesy egg mixture on top.
3. Pop it back in the oven and bake for another 25–30 minutes at 180°C (350°F), until it’s golden and set.

Time to serve!

Let it cool for just a few minutes so everything settles. Then slice it up and serve! It’s amazing warm, but honestly, it’s also delicious cold, perfect for a picnic, lunchbox, or midnight snack when the kids are finally asleep and you need a little moment for yourself.

When to Serve This Onion Tart

This tart has made its way to Easter brunches, New Year’s Eve happy hours, summer garden parties, and even “Mom needs a break” Tuesdays. Here are a few fun ideas:

• Appetizer: Cut into small squares and serve on a tray. Fancy and fuss-free.
• Brunch: Pair it with a mimosa and a fruit salad and watch your guests swoon.
• Dinner: Serve with a green salad and maybe a glass of wine, dinner done.
• Party food: It holds up well, even after cooling, so it’s perfect for buffet tables.

If you’ve never tried an onion tart before, this is your sign. It’s simple, comforting, and just a little bit fancy. It tastes like something you’d get at a café in France, but it’s made right in your cozy kitchen.

So roll up your sleeves, put on your favorite playlist, and give it a go. And hey, if your family falls in love with it too, don’t be surprised if it becomes one of your new signature dishes.