📖 Instructions

1. Preheat your oven to 400°F (200°C). This is crucial for a perfectly baked tart. Seriously, don't skip this step!
2. On a lightly floured surface, roll out your puff pastry to a 12-inch circle. If the dough cracks, don't panic. Just patch it up gently with your fingers. It's more forgiving than you might think.
3. Carefully transfer the pastry to your 9-inch tart pan. Gently press the dough into the bottom and up the sides. Trim away any excess pastry; you can totally save the scraps for another day.
4. Prick the bottom of the pastry with a fork several times. This prevents it from puffing up during baking. Trust me on this one.
5. Line the pastry with parchment paper and fill it with pie weights or dried beans. This is called blind baking—it stops the base from becoming soggy. Genius, right?
6. Bake the pastry shell for 15 minutes. Remove the weights and parchment paper; return it to the oven for another 5-7 minutes, until lightly golden.
7. Meanwhile, let’s make those caramelized onions! Melt 2 tablespoons of butter in a medium saucepan over medium heat. Add 2 large onions, thinly sliced. Cook, stirring occasionally, for 20-25 minutes, until deeply golden brown and caramelized. This takes patience, my friend. But it’s worth it.
8. Stir in 2 tablespoons of sweet paprika and 1 teaspoon of salt into the caramelized onions. Cook for another minute, stirring constantly to coat the onions evenly.
9. Remove from heat and let the onions cool slightly. This is important so you don’t melt the cheese in the next step.
10. Spread the caramelized onion mixture evenly over the pre-baked tart shell. If you’re feeling fancy, maybe sprinkle some extra paprika over the top!
11. In a small bowl, whisk together the two eggs, half-and-half, and salt and pepper. Slowly pour this mixture over the onions.
12. Grate 1 cup of Gruyere cheese over the top. I know, Gruyere can be pricey, but boy is it worth it. Alternatively, you can go for a cheaper cheese, or maybe a cheese you got for free from a neighbor, whatever you have!
13. Bake for 25-30 minutes, or until the crust is deeply golden and the filling is set. The best way to check is to gently jiggle the tart – it should be firm.
14. Remove from oven and let the tart cool completely on a wire rack before slicing and serving. Patience, again! But the wait is rewarded with a flavor explosion. Enjoy!