Decadent Caramelized Onion Tart (Printable)

Rich tart featuring caramelized onions, goat cheese, and flaky pastry, perfect for brunch or a savory treat.

# What You Need:

→ Crust

01 - 1 sheet ready-rolled puff pastry (8.8 oz)

→ Caramelized Onions

02 - 2 tablespoons olive oil
03 - 2 large yellow onions, thinly sliced
04 - 1 tablespoon unsalted butter
05 - 1 teaspoon sugar
06 - ½ teaspoon salt
07 - 1 teaspoon fresh thyme leaves or ½ teaspoon dried thyme

→ Filling

08 - 5.3 oz goat cheese, crumbled
09 - 2 large eggs
10 - ½ cup heavy cream (120 ml)
11 - ¼ cup whole milk (60 ml)
12 - ¼ teaspoon freshly ground black pepper
13 - ¼ teaspoon salt

→ Garnish (optional)

14 - 1 tablespoon chopped fresh chives or parsley
15 - Freshly cracked black pepper

# How To Make It:

01 - Preheat oven to 400°F. Line a 9-inch tart pan with the pastry, trim excess, and prick base with a fork. Chill for 10 minutes.
02 - Heat olive oil in a large skillet over medium heat. Add sliced onions and cook, stirring frequently, for 10 minutes until softened. Add butter, sugar, salt, and thyme; cook, stirring occasionally, until onions turn deeply golden and caramelized, about 20–25 minutes. Remove from heat and cool slightly.
03 - In a bowl, whisk together eggs, heavy cream, milk, black pepper, and salt until smooth.
04 - Spread the caramelized onions evenly over the chilled crust. Sprinkle crumbled goat cheese evenly on top.
05 - Gently pour the egg mixture over the filling, ensuring even coverage.
06 - Bake for 25–30 minutes until set and lightly golden. Remove from oven and cool for 10 minutes before slicing.
07 - Optionally garnish with chopped chives or parsley and extra black pepper. Serve warm or at room temperature.

# Expert Hints:

01 -
  • It tastes fancy but uses ingredients you probably already have, and nobody needs to know how easy it actually was.
  • The onions do most of the work while you clean up or pour yourself a glass of wine, and the payoff is this deep, jammy sweetness that makes everything else shine.
  • You can serve it warm, cold, or somewhere in between, which means it travels well and never disappoints at a potluck.
02 -
  • Do not rush the onions, high heat will scorch them before they sweeten, and you will taste the bitterness in every bite.
  • Chill the pastry after you line the pan or it will shrink away from the edges and leave you with a shallow, sad tart.
  • Let the tart rest before cutting, the custard needs time to firm up or it will ooze everywhere and look messy on the plate.
03 -
  • Taste your onions halfway through caramelizing and adjust the salt or sugar, every onion is different and some need a little more coaxing to turn sweet.
  • Blind bake the crust for five minutes if you want it extra crisp, just line it with parchment and fill it with dried beans or pie weights before the filling goes in.
  • Let the tart cool completely before slicing if you are serving it at room temperature, the flavors deepen and the texture sets perfectly when it is not piping hot.
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